- Welcome to Ars Technica Live. This is a monthly series that we do here at the lovely Eli's Mile High Club which is providing us with this space so please buy lots of food and drinks. Ars Technica Live is also sponsored by Ars Technica which is a fantastica publication, arstechnica.com. We publish lots of stuff about technology and science and culture. And in fact, that's how I first met our guest tonight, was by writing an article for Ars about Argentine ants. I'm Annalee Newitz. I am the Editor-at-large for Ars Technica, and this is Neil Tsutsui who is my guest tonight. I'm super excited to ask him all the questions about ants. He is a researcher and professor at Berkeley who studies ant communication. I guess technically you're an ecologist? Is that the right? - No, I'm more of a behavioral ecologist. - Behavioral ecologist. - Yeah. - And he also does a lot of citizen science work, which we're gonna talk about, and which you can get involved in as citizens, and even as non-citizens actually. You don't actually have to be, you just have to be a citizen of science, not of the United States. So I, I have like 20 million questions, but I am going to start by asking you, since you study ant communication, can you just tell us, how do ants communicate? What are they doing when they're communicating? Just give us like a crash course in how they talk. - Okay, so ants, the way they communicate is completely foreign to, you know, our experience of the natural world. So we're visual creatures. Humans are visually oriented organisms. So we go out in the world, we look at faces, and we recognize people we know. And we recognize faces that we hopefully haven't met before. And we see doorways and pathways and sidewalks and we do all of this visually. And we're auditory as well. But we're primarily visual creatures. Ants, and most insects actually, are not visual creatures. They're chemically oriented creatures. They use chemo-sensory biology to navigate their world. And so this is especially true for ants because ants are, you know, we experience ants in our kitchens and in businesses above ground, but ants are actually largely subterranean, right? And so they live in dark places where vision doesn't work very well. And so they use chemicals for almost everything they do. They use chemicals to recognize each other, to determine not only who's a member of my colony and who's not, but, you know, what is the cast of characters within my colony? So, who's a baby? And how old are you? Who is a forager and what type of food have you returned with? They use chemicals to tell other nest-mates where to find food. And we've seen this probably with Argentine ants, they lay down foraging trails that guide other ants to food resources. And then those chemicals-- - [Annalee] So when you see a trail of ants, they're actually following a trail of chemicals. - That's right. So, you know, at the beginning a scout has gone out and found food and is really excited about it, and so comes back to the colony and on that return trip leaves a trail of trail pheromones, and then other ants go and they go out into the world to forage, they find this trail, maybe by chance, or maybe because it's, you know, directly leaving from the colony entrance, and so they will follow the trail and go to the food, and if they like what they find then they'll reinforce that trail on their way back. And after a few ants do this, you start to, you know, get these really massive foraging trails that, you know, you see sometimes going to like the dog food bowl or to the, you know, honey container that you left out on the counter. - [Annalee] So how did they, so you say they're using chemicals, so how are they, how are they sharing those chemicals with each other? Are they like squirting them in the air? Are they, how do they pick them up from each other? - Yeah, and so it really varies. So there are all kinds of different chemicals. So you know, for things like alarm pheromones, so if an ant is startled, it will release an alarm pheromone and, you know, the best alarm pheromones are those that travel to your nest-mates really quickly. So these are small molecules that are volatile, so they travel through the air. - So they're like literally squirting, I mean. - Yeah, or they're just exposing them in liquid form to the air and they evaporate off, and, you know, diffuse through the air, like the smell of tater tots from a kitchen. [laughter] - Warning, there are tater tots. [laughter] - That's right. Right, and then you can have, you know, chemicals like trail pheromone that are for its use, so those are intermediate size molecules. They persist for a little while on a substrate, but if nobody reinforces the trail for a while, they evaporate away. And then you have very large molecules that are persistent. They're not volatile at all. And these are types of things that are on the exoskeletons of ants, and those are used as fairly permanent identification tags, so these are called cuticular hydrocarbons. They're waxes at room temperature, and-- - So ants are covered in smelly wax, basically. - Yeah, smelly wax, and a wax that smells like home, right? - And so when they run into another ant, they sniff that ant with their antenna and they say, do you smell like, you know, my nest-mates back home? And if you do, you're a buddy of mine, and I'm gonna, you know, go on my way, or clean you maybe. If you smell like a different colony or a non-relative, then I'm probably gonna attack you. - So when ants are touching each other, when we watch ants touch each other, that's, they're smelling each other. - Yeah, well, you know, antenna, they smell with their antenna. They also taste with their antenna. And so antenna are these interesting organs that are like a combination of noses and tongues, right? So they're like slapping them on each other both tasting and smelling. - So what are some of the things that, in your work, you've been able to decipher that ants are saying to each other? You talked about trail pheromones, so that's kind of like, go here, and a warning pheromone, so what are some of the other things that they're communicating? - Yeah so, so we've identified a lot of these types of pheromones that I've just described to you. So one of the ones that we're initially really interested in and that got us into this field of chemical ecology, trying to sort of decipher their language, is you know, trying to figure out what are these cuticular hydrocarbons that distinguish ants from one nest from another? Like, how do they recognize who's a colony-mate and who's not? This is especially important for Argentine ants because, as some of you may now, Argentine ants form these, like, really huge colonies in their introduced range, like California, and the basis of that is the fact that ants from throughout California have similar colony odors. And so they're sort of all wearing the same uniform, or they all smell like relatives, right? And so, you know, if you look at the exoskeleton of ant, they are tons of chemicals there, right? There are like 90 something chemicals that you can extract from a ant's body. And only a small subset of those are used for this. And so that was a big effort for several years, trying to tease out which of these chemicals amongst this, you know, huge mixture are the ones they're using to recognize nest-mates and the ones that are not. And we found a bunch that correlated with behavioral differences, when ants recognize that another ant is from a different colony, what chemicals are different. And then we had a chemist synthesize some of these for us in pure form. And so then you can do the fun experiment, where you take an ant, right? And you put a different chemical on it from a different colony and you throw it back in its nest, and you see if it gets attacked or not. And it does, right? [laughter] It's like, you know, a sophisticated version of what, you know, seven year old kids are doing all around the country right now. - So how are you doing these experiments in your lab? Like, what are the tools that you're using? You're cooking up ant chemicals, and like, what are you, where are you keeping the ants? How are you doing all this stuff? - I mean, we do all kinds of stuff. So this chemical ecology is, you know, I would say maybe 20-25% of what we do. We do a lot of genetics and genomics, so we do like sequence mitochondrial DNA to reconstruct evolutionary history of organisms. We do DNA fingerprinting to estimate relationships among individuals, and we do whole genome sequencing to look at parts of the genome that are evolving in particular ways. And then we do some old-fashioned field work, or people in my lab do. And, you know, so they go out and, you know, in many cases they're interested in studying organisms, you know, the way graduates start, they want to have an adventure, right? So they typically want to do a project that's in some far-flung location that's tropical, right? And so we have students doing field work on projects looking at symbiotic ants. So when two different species come and live together in the same colony. It's an unusual sort of extrapolation of ant social structure, so now we have two species that are living in a mutualistic symbiosis, and they partition their behavior. As one forages and one defends. I have a student who has worked in Indonesia looking at seed harvesting ants. So we do, there's a little bit of field work. And then we do a lot of behavioral experiments in the lab where we're-- - [Annalee] Yeah, tell me about these behavioral experiments. - Yeah, so we can do things like, you know, so Argentine ants, you know, do really well living in artificial conditions like houses. And that means that they're also good lab organisms, so-- - So just to clarify, you've probably all met an Argentine ant. - [Neil] That's right. - They are very common in cities. They're just the little teeny tiny brown ants that have invaded your house probably multiple times. - Yeah, I mean, so if you've been in an urban area in California, or if you've, like, especially in the Bay Area, right, and you've seen a small dark brown or black ant, or you've had ant problems in your house or business, this is the species, almost certainly. And so it's a non-native species. It's been introduced from South America. And so they do well in the lab, and so we can create colonies for all kinds of different experiments. We can, they have many queens per colony normally, and so we can collect a big fragment of them from the field. They can be separated out from the soil real easily because they evolved in floodplains in Argentina, and so we have a big tub of dirt with a whole bunch of ants. We let them find their babies and get organized for like, a day. And then you can slowly start to drip water into this tub and they'll evacuate everybody out of that tub over a wire bridge into a new container. And so you just end up with a bucket full of ants, right? And then you can divide them up into experimental units, right? You can make colonies that have, like, 100 queens and 100 workers. Or colonies that have one queen and 10,000 workers. And you can take ants out of the colony and switch chemicals that are on their bodies and put them back in. Or you can give them babies of different ages. Or you can switch babies between colonies. You can do all kinds of fun stuff. - All kinds of nefarious activities. [laughter] - Yeah. - When I was talking to you earlier, you mentioned that you can actually make an ant fetch. How does that work? - Yeah, so, I mean, like I said, you know, the ants live in a chemically oriented world. And so if you alter the world in a way that makes sense to the ants, they'll, you know, behave accordingly. And so we've done experiments where, you know, you can extract the chemicals off of the brood, so that's the larvae and the pupae in the colony, the babies. And then you can put that on other objects, like a small piece of filter paper or a little piece of styrofoam. And you can give that to the ant, and they'll retrieve it back into their colony as if it's a baby. Or they'll take it over the bridge when you're flooding them thinking they're saving their babies. - But they're just saving styrofoam. - Yeah, they're saving the styrofoam, right. - And so do they ever figure it out? Like, do they ever reach this point where they're like, they're trying to feed the styrofoam and they-- - Yeah, we haven't taken that far yet. [laughter] It would be interesting to see. Maybe we'll line that one up for the summer. - But that's how you would get them to fetch, is you're basically saying this a baby, so go get that. - Yeah, or you can, and we identified the trail pheromones for Argentine ants, and so we can draw a chemical trail and lead ants to where we want them to go. People are experimenting with incorporating this into control strategies, so, you know, in an effort to try and reduce the amount of insecticides that we're dumping out into the world. You know, if you can increase attraction to insecticidal bait, you can use a lot less insecticide. And so if you mix these trail pheromones in with a bait that has insecticide in it, you get orders of magnitude more ants showing up and feeding on it. - So we were talking about this earlier too, about the question of whether, when you're doing things like that, if you're communicating with the ants the way you might communicate with the dog when you say, like, fetch! And the dog gets it, right? Or is it more like programming the ants, because you're just sort of telling them to go to a place. What do you, or is it somewhere in between? - Yeah, I don't know. I guess it's hard to say. I mean, so we've, you know, you can identify commands in their language, right? And you can issue those commands to them. You know, here, follow this trail, you know? Accept this baby. Kill this non-nestmate, right? [laughter] - Okay. - And so it's, you know, unidirectional communication in that respect, in that we can use their language to tell them to do things and they do them. But, you know, we haven't really been able to close that loop, right? So we haven't really been able to establish like any sort of back and forth communication with them. - [Annalee] Yeah, so the ants have never said to you, like, stop giving us styrofoam babies, or whatever? - Yeah, not yet. - [Annalee] Because it's too complicated, yeah. - Not yet, we're getting there, though, I think. It'll come soon. - So one of the things that's super fascinating about ants, I think, for a lot of people is this idea that they're social insects and that they're kind of like a hive mind, or some kind of collective consciousness. Is that right? Is it true that they're kind of like a hive mind? Or are they much more individualistic than we realize? - Yeah, I mean I think there's a little bit of both, right? So there, you know, you have individual ants in a colony that are doing their own particular thing, right? So they have their tasks. And so a forager goes out into the world and collects food. And a nurse takes care of the babies. And guards might stay at the entrance of the colony and check everybody who comes in. And so they, they're individuals in that they have a sense of the world around them based on those first hand experiences. But at the same time, they communicate aspects of their experiences to other individuals. So, you know, a forager can return to a colony with food and initiate recruitment. So other, you know, recruit other worker ants that may not necessarily be foragers to the foraging task. Like, there's a food resource, it's especially rich, that shows up on the territory. Everybody go collect this. And so, you know, they communicate their experience of identifying, of finding this really rich food resource to other individuals, and then they might respond to it in a way that allows them to, you know, optimize their foraging of it. And then once they've depleted it, they go back to their normal tasks. And so, you know, in that sense it's a little bit of a hive mind, in that, information is distributed among different individuals and they can, you know, respond sort of as a fluid super organism, right? And so they can, as a colony, at the colony level, they can modify their behaviors in response to the world around them. - But as individuals they can change their behavior too. It sounds like they can be-- - That's right. - Maybe in the middle of doing one thing, and say, oop, gotta go clean something up, or go, you know, get some food, or whatever. - Yeah, so they have sort of a baseline behavior. So they undergo this process called age polyethism. So, you know, young ants will emerge from pupation, right, they're pupa, they emerge as a worker ant like we're familiar with. And then they do tasks around that place where they emerge for the beginning of their life. So they serve as nurses, they clean the babies, they move the babies around. And then they sort of graduate to tasks farther away. They might collect food from foragers and distribute to other individuals. And eventually they progress through different tasks as they age. And then the most dangerous task is done by the oldest workers, which is foraging. The same is true for bees also. And so there's a baseline behavior that each individual has that provides them with experiences based on those behaviors, but then it's a network in the sense that, you know, they can communicate their perceptions of the world to others. And so there is some flexibility. It's not, these task, these baseline tasks are not hardwired and absolute. They can be plastic and modified. - So there's also a huge range of ant behavior as you go from species to species, right? So what are some of the weirder and more interesting behaviors you've seen? - Oh yeah, ants are so cool. I mean there are so many ants that I-- - I know. [laughter] - Right, yeah, so they're really great. So, you know, so there are probably about 14,000 named species of ants. There are probably about 20,000 species of ants out there in the world. And they do all kinds of different things. You know, and you're maybe familiar with some of these. You know, like army ants, right? So army ants especially in the tropics are abundant predators. We have army ants here in California, in northern California actually, that are specialist predators on other species of ants. We hardly ever see them because they're almost exclusively subterranean. They tunnel underground until they find a colony of a different ant and then they just raid that colony and kill everybody and eat everybody and hang out for a little while a move on. There are ants that perform agriculture. So fungus growing ants has been a really successful group. These leaf-cutter ants that you see on Discovery Channel do that. These leaves that they're harvesting and bringing underground, they're not eating the leaves. They're mashing them up and then growing fungus on them and consuming the fungus as food. There are slave-making ants. And so, my lab has a research project looking at this, there's a species of ant in the genus Polyergus that, you know, if you look at these ants, they don't look like normal ants. They have these, so normal ants have like utility tools for mandibles. They're serrated edges, they're really robust and strong. They can use their mandibles for attacking enemies or picking up a fragile egg, or moving soil. They can use their mandibles, most ants can use their mandibles for lots of different things. This species of ant, if you look at their mandibles, they're these like curved sickle-shaped mandibles and they're useless for all of those tasks. They can't feed themselves, they can't hunt, they can sort of defend their colony. They can't excavate soil, or chew through wood. But what they can do is kidnap babies of other species of ants. And this is what they do. This is how they make their living, right? And so you can see this, you know, throughout California during the summer in the afternoon. You know, these Polyergus will, a scout will go out earlier in the day and find a target colony, and it returns to its home colony, and it will gather together a group of workers into a raiding party, and then they will launch a raid on this particular identified colony on that day. And they go in, and they use pheromones, and they attack this colony, they use pheromones to confuse everybody, and they do some fighting, and this other colony tries to repel the Polyergus, but then most of the workers, they're really good at this, they run down underground, and they find the babies, especially the older larvae and the pupae, and they grab them, and then they retrieve them all back to their own colony. And the reason that they don't have to do all this work and don't have to have all these multi-tool, you know, mandibles is because these kidnapped individuals do all the work in the colony. They emerge from pupation, they imprint on the odors around them in their colony, and for the rest of their lives, they perceive as if it was the colony they were born into. Right? And so all of these slaves do all the work in the colony. They do all the colony defense, and all the excavation, and all the foraging, and all the baby care. And so a single Polyergus colony specializes on a single host species. So all the slaves in the colony are of a single species, but they've been raided from dozens of colonies in the surrounding area. And one of the interesting things that we found at the study site we've worked at, that we studied them in, the Sierra Nevada, is that, at this site, you have Polyergus colonies scattered across the landscape, and like I said, each individual colony only uses one other host species, but there are three possible other species they can use as slaves. And so you might, in this colony they're enslaving species one, and this colony they're enslaving species two, in this one they're enslaving species three. And there's a mixture of them. And then, and so, you know, we've collected these ants from these colonies and done genetic analysis of them, and it turns out actually that the lineages that are using species A, species one, species two, species three. I forget if I was using numbers or letters. But these lineages that are using different hosts, or different slaves, have started to diverge from each other and form species themselves. So they're becoming genetically different from each other and there are barriers to hybridization among them. And they're becoming more and more specialized on that particular species they use. And so it looks like this neat model for a speciation which is like, a fundamental concept in evolutionary biology, where we have these Polyergus colonies that are using different slaves are at the very, very beginning of this process. - Wow, and so what are these slave-masters doing while their slaves are working? Are they just hanging out being lazy ants? - Yeah, they're just, they're hanging out. They're making more, their queen is making more of their own babies. And the way these colonies get started is crazy also, right? And so, so you have a colony of Polyergus, right? And you can tell that you have it because you dig into it and it's a mixture of two different species, you have Polyergus and you have the slaves. And once these colonies attain a certain size, you know, after three to five years of colony growth, then they start to produce new queens and males, the reproductives. And then late in summer, during one of these raids, the, new queens will go out, or a new queen, will go out on a raid with one of these raiding parties of her sister's, the workers, and as they're stealing the babies from the colonies they're raiding, well before that, so they go out on the raid, she emits a pheromone, she calls in males from other colonies, she mates, and then as this raiding party is stealing all the babies from the colony they're attacking, she runs inside, she finds the queen and kills her. And then she becomes the new queen within that colony. Right, she sets herself as the new queen. So here she is, this is how Polyergus colony starts. This one lonely, brave queen who has assassinated the queen in her host colony and is surrounded now by all, every worker around her is of this other species. And then she starts producing her own workers. She lays her first eggs, and her slaves take care of them. And once she has, you know, a dozen of them, they go and they conduct their own initial small, cute little raids, right? And then, you know, because she has killed the host queen, right, this is like a zombie colony, you know, it's kind of a race against time, because the population of the workers, slaves in this colony is gradually dwindling as they die from old age or from being eaten or whatever, right? And so it's a race for her to produce enough workers to conduct successful raids to again, re-establish, to lift the numbers and replenish the numbers of slaves that have been lost by attrition. It's an amazing system. - We'll have questions later, yeah. I have so many questions, too. So, it's so interesting because, it's so tempting when you hear about ant colonies and ant behavior to anthropomorphise them, because that sounds like a great metaphor for imperialism. - [Neil] Right. - Like, I could just imagine all of the stories that could be written about that. And I guess my question is, what is it that makes, I mean, when we think about human behavior, you know, we gather into cities. We have slaves. We farm. We do a lot of the things that ants do. Why are we not a social organism like that? What makes us different? - Well we are a social organism like that. - Or a super organism like that, yeah. - Well we are a super organism. - Okay, all right, no, I think so too. - I think we are. I mean, I think, you know, the ants have taken it to another level, and you know, so we have, we have exactly the same thing in our societies that many of the same things that ants do. So we have division of labor, right? You know, we're all specialists, there, I think, there are probably none of us in this room that, you know, grow our own food, and hunt for our own protein, and then, you know, tan hides for our clothes, and things like that. - Mine for oil. - Yeah, there might be somebody in here, but, so, and so in that way, you know, I think, you know, these are just sort of, we've independently evolved, or discovered sort of fundamental truths of efficiency of work, right? - Mhm. - In societies, and so, we've independently evolved this sort of same things. But then ants, and other eusocial species have taken it another step further in that they also have reproductive division of labor, right? And so this is where we get into the more sci-fi realm. In that they've sort of, you know, optimized their colony output by having a specific caste of individuals as reproductives and a specific caste as non-reproductives. And it's just sort of like division of labor taken to another level. But that's one of the things that defines eusociality as a social structure that's more advanced than ours. - Wow, yeah. So let's talk a little bit about your citizen science projects. - Sure. - So I know you've worked on this umbrella organization called Backyard Biodiversity and you've had people sending you samples of dead insects that they've found in their pools. - Right. - So tell me about that. How's that going? - Right, yeah, so the Backyard Biodiversity project is sort of, it's a project that I co-founded with Brian Fisher who's a curator of ants at California Academy of Sciences. And together we wanted to develop projects that get people engaged in the natural world around them. I think, you know, for lots of us who are scientists, you know, we started this at a young age and we like to pass that on to, you know, other youngsters who might have that predisposition as well. But also there are tons of people, many of whom are in this room, who still sort of maintain an interest in the natural world and are always looking for, you know, fun new ways to engage with it. And so what we tried to do is come up with a variety of different projects and tasks that, you know, do that. That engage a variety of different people and that also can contribute something meaningful to science. And so one of these projects is the Pools Project. And so we have about 15 or 20 pools throughout California where people have signed on to scoop the insects out of their pool once a month and send them to us. And we use this as a way of measuring biodiversity. A new way of measuring biodiversity. And there are some amazing things we found from that. So there's a pool in Marin County, actually the first one that sort of inspired this project, that revealed these Dracula ants that are incredibly rare ants. They're called Dracula ants because, so they're also subterranean, you hardly ever see them above ground, very, very rarely. And they make their living, one of the ways they feed, is by drinking the blood of their babies. So workers will pierce their babies with their mandibles, and drink a droplet of their Hemolin, their insect blood. And the baby is presumably fine, but it's a way of, you know, sort of, you know sustainably harvesting the food from others within the colony and distributing it sort of more equitably among individuals in the colony. - [Annalee] So there's Dracula ants in Marin. That's our takeaway message. - We found, yeah, they are there. There are also army ants in Marin. And so we found these in one of our pool collections. And the reason we found them is because occasionally during the year, they will release their reproductives, their winged new queens, and their males, who will fly, they go on these nuptial flights, they mate, the males die, and the queens go off and disperse to found new colonies. Well sometimes they fall into pools. And maybe they're attracted to light, or maybe they're attracted to the water. But we, you know, found them in astonishingly high numbers compared to how rare they are seen above ground in sort of, any other way. We have an ant-vasion project for as part of the Backyard Biodiversity project where there are, you can get a kit to do this experiment. There's a card where you can put down bait on two different places, and you put sand around one of the baits as a control, and then you put some sort of spice or herb around the other one. And this project was inspired by what is probably the second most common question that I get as an ant biologist. You know, people will come up to me and say, you know, I heard, you know, from my grandmother, that paprika is the best thing to control ants. You just put it around your doors, and they'll never come in. It'll solve all your problems. Or it's, in some versions it's black pepper. In some versions it's vanilla oil, or something. - [Annalee] I heard it was orange juice, actually. - Yeah, so there we go. - [Annalee] Which doesn't make any sense, I realize, 'cause they, yeah. - Orange juice. Could be, so, we could add that. And so this is a citizen science project designed to test that. We send out this test kit that has the card, the baits, and it has vials of different spices, and you can run this experiment in your house. And after you've put out the bait and ants have recruited to it, you send a picture of the bait to us, and we can see which ones that, which one the bait has gone to and if the spice has indeed repels the ants. And actually, the Girl Scouts have just adopted this as one of their, as a project that they can do for a merit badge in Think Like a Scientist, so. - [Annalee] That's so awesome. - Yeah. - Yay, Girl Scouts. So, but you haven't gotten any data from that yet? - [Neil] We have, it's trickling in. - Which one really works? - It's a little spotty, because it's hard to identify the ants, and people do it different ways, and then there are innumerable permutations, and people don't follow directions, and so, we'll have to let it run for a couple more years. - You're gonna wait for more data, yeah. And then any new citizen science stuff on the horizon? - Yeah, so we're starting to launch projects that are, that sort of couple experiences outdoors and learning about biodiversity with sort of biological assessments, or biodiversity assessments. And this is, who here has, has anybody heard of a BioBlitz? Or, no? One? Or the, has anybody heard of the City Nature Challenge, which took place just a couple weeks ago? Yeah, so, it's a target-rich environment here, for me. So you should all do this, then. - [Annalee] They are super awesome. - Right, so you can go to my lab's web page, or you can go to BackyardBiodiversity.org, and you can sign up if you're interested in doing this. And what this is is we have, you know PhD students, and post doctoral researchers who are experts in insect biology who are mentors and we, you know, will take, we take out groups of learners, and this, these are learners of all ages. We want to do K-12 groups, we did college students a couple weeks ago. Our next one will be sort of post-college millennials, if there are any in the room. And you can sign up and do this. And you know, so we'll have, you know, groups of probably like, three learners, that go out with a mentor, and will go to some natural area, like a regional park, and do like an intensive biological survey. So you know, we'll show you how to catch insects with a sweep net, and how to find insects on vegetation, and we'll have pitfall traps out and you can look and see what we caught overnight. And so we're trying to, sort of record as many species in a small restricted area as possible over a short amount of time. And this is valuable information for regional parks and for us, knowing what species are out there and where they occur and where they don't occur. And it's also an opportunity for people to learn what species, just learn how to identify different things. If you've wondered what that's crazy bug, or what's this yellow flower, this is like, the perfect way to do that. We use iNaturalist as a platform, this is an app that you can download. And even if you don't do one of our backyard biodiversity projects, you can still download the app. It is by far, I think, the most effective way to learn what different species are, to put names to things you find out in the world. Just take a picture and it will be crowdsourced. Identification will be crowdsourced. Yeah, we have tons of other projects, so. - That's awesome. So before I open it up to audience questions, I wanted to circle back to something that you mentioned kind of the very beginning where you were talking about how your lab also does genetic studies. And I know that you worked on a study recently about honey bees in California and made some really interesting discoveries. So we are talking for a brief moment about bees. I know I promised more bees. - Yes, most of you are probably here for the bees, right? - So what did you find out? - Yeah, so right, so where to begin? So bees are also an introduced species. Honeybees are. The bee that we're familiar with, on flowers. They were introduced from the old world, so they're native to Africa, Asia, and Europe. And so they were introduced by the first missionaries that came over when they were building the missions, they brought honey bee hives with them, mainly for hive products. So things like honey, propolis, and wax. And then, you know, through the years we've grown honey bee operations. Honey bees are now used, actually, most commonly for pollination services, not so much for those hive products, but bees are an abundant part of the ecosystem. People notice them and so they're well represented in insect collections. And so for this project we found, we surveyed entomological collections throughout California, and there are tens of thousands of honey bees that have been collected into these collections. And what we did is we identified places where bees had been collected at multiple time points through the years. - Wait, what was your, oh go ahead. - Yeah, so our oldest one goes back 125 years. - Wow. - And so, you know, on Catalina Island, and many of them we have go back 50, 60, 80 years, some of these sites. And we have multiple, so we have bees that were collected at these sites for 80 to 125 years multiple times. And each of these individual bees is a time capsule, right? So it not only contains information about who it is in the colony it was born into, but it contains information about the diseases that bees get, you know, got during those times. And they have pollen on their bodies. And so we can see what plants they were pollinating on their last day before an entomologist collected them. And so we brought the, you know, we got these bees from these different collections and we extracted DNA from them, we did whole genome sequencing, and so we were able to reconstruct evolutionary history. We're in the process of identifying the pollen and the plants, and identifying pathogens. But from the genomic studies, we found an interesting pattern, actually three interesting patterns. And so bees have changed dramatically in California since their first introduction. In Southern California they've changed in a way that you probably are familiar with. So the African subspecies of honeybees, Apis mellifera scutellata, was accidentally released in Brazil, and has spread north, right? These are the Africanized killer bees that we've seen the scary headlines about. And so they've actually made it into California and you can see a clear signature of hybridization of this subspecies, African subspecies into the background of the pre-existing European bees that were there. So the genome has changed in, pretty dramatically. Also, what's interesting are the things that have stayed behind, so presumably those are parts of the genome that have some adaptive evolutionary function. Here in Northern California, they've changed as well, equally dramatically but in a different way. So the first bees that were introduced by the missionaries were called the German black bee, Apis mellifera mellifera, and nowadays, pollination operations use these, you know, big orangish bees that we see now. These are Italian subspecies and we can see a clear signature in the genome of this shift in management practices and in the things we used bees for. So these Italian genomes have hybridized into the background of the pre-existing German black bee background. And then on Catalina Island, one of the channel islands in Southern California, this is a little time capsule also in itself in that it hasn't experienced either of these big changes and is essentially still German black bee, the same as those that were introduced from, you know, long ago, and it sort of represents the, this, you know, a snapshot in time from early bee keeping operations in California. - So basically what you're able to see it sounds like, is sort of the changes that humans have made in the bee population by introducing new species, or-- - That's right. And we can see changes, actually, we can see impacts of human environmental change on these bees also. So we analyzed stable isotopes in their bodies and by looking at isotopic compositions of nitrogen and hydrogen in the bodies of bees, we can see a clear signature of air pollution, and the burning of fossil fuels. So from sites that are downwind of large cities in both Southern California and Northern California, we see a big shift in these stable isotope ratios but then in our more pristine populations, from like Mount Tam, or other places that are not downwind of big cities, we don't see that shift. And so this is probably occurring through the food chain. It's probably changes that are being manifested in the plants, and then the bees are consuming nectar and pollen from the plants, and it's changing their bodies as well. - So interesting. Okay, so I'm gonna open it up to questions. I'm gonna very awkwardly take my microphone off this stand. If you want to ask a question, it would be great if you just like come up here. You can like, line up and ask what you wish. If I can, thank you. - [First Audience Member] Yeah, so I'm curious about the, some of the behavioral and, I guess if you think, like, animal psychology. One is, if there's some way to investigate why it is that the ants would like to enslave the other kind of ants, as opposed to say, raising a sub class of their own? And the second is, when a queen assassinates, does the colony then take on the flavor, or the, some different behavioral change based on the new queen? - Yeah, those are two great questions. And so, the answer to the first question is, you know, so, this is basically a way of cheating, right? And so, you don't have to invest, if you're Polyergus, the slave-making ant, you don't have to invest your energy so much in producing your own workers to attain a population size that really can effectively harvest resources from the environment and sort of continue the colony growth, right? And so it's a way of sort of short cutting the normal, you know, painful colony growth that most normal ant species have to go through. In the case of when a new queen takes over a host colony, so one of the first things, it seems like one of the first things she does, is acquire the hydrocarbons from that host queen on her own body and that disguises, potentially disguises her as the queen in that colony, and so that may be a component of the acceptance by that colony of her. But then, obviously as time goes on, you know, they're adding slaves to this colony, and so the composition of the worker force in the colony is changing as they're getting workers from different colonies that are genetically different from each other. And so there has to be some level of neuroplasticity in, that allows them to accommodate these new odors, and sort of incorporate them into their, sort of, neural definition of what a colony is. And that hasn't, that hasn't really been thoroughly studied, but it's certainly an area that I think we'll, is worth looking into. - [Second Audience Member] Along the same lines with slaves, why don't they enslave the queen of the brown ant, the Argentinian ant, when they go in? Why don't they just enslave her, and that way they can keep the colony going, and they can just rise on top. - Right, so the Argentine ant is a species we have around here. So that's the little small dark brown or black one. Polyergus, the slave-making ant that I was talking about is a distantly related species, and it looks really different than Argentine ants, so it's living a completely different life. There are these, Polyergus is a fairly large red ant, and you won't see them around here in urban areas in places where Argentine ants are, but you will see them in more natural areas, in the Sierra Nevada, even out in Point Reyes. And so I'm not sure exactly what the rest of the question was. - Why don't they enslave the queen instead of killing her? - Oh, right, so I don't, so that's a good, So I don't know why, in that case, they do kill the queen. It's certainly not the best way to do it. And there are other types of social parasites, so there's one that I've studied in South America in Argentina that has a similar, well, it's an even more extreme form of this social parasitism that the new queens will disperse, they'll go into a colony of their hosts, which happens to be a fire ant, and the queens will find the host queen, but they won't kill her. They just latch on to her and ride piggy back for the rest of their lives. [audience laughter] And so it's a much better way of doing it, right? And so then that queen, right, is producing new workers. You don't have to go out and raid at all, and they don't. This is not a slave-making ant. It's an obligate social parasite that, you know, it goes into these colonies and then all the workers are still able to be produced by the host, but the queen, who's the social parasite, in these species have completely lost the ability to produce workers. They don't produce workers at all. They don't need to any more, right? It's become like a vestigial organ, or something. And all they do is produce new reproductives, new queens, virgin queens that mate and go off and start new colonies and new males, right? And so there it's like the best-case scenario from an evolutionary perspective, right? Because all of their energy is focused on transmitting genes to the next generation. There's none of this, like, producing these workers that are sterile and essentially useless from a fitness perspective. And so there are species that do what you're alluding to. - And you get a free ride for your whole life, right? Because you're riding on top of the-- - [Neil] That's right, yeah, you're just hanging out gettin' fed, gettin' protected, gettin' cleaned. - So this is about your work, and, does the University have the same requirements for working with insects that they would with mammals or animals around ethics? And what's it like, for you, like if you wipe off a ant's pheromones and stick it into the colony, and then it gets killed, like do you ever feel guilty? [laughter] - So, interestingly, from the perspective of the University regulations, insects are not animals. So biologically that's not accurate, but in terms of animal use policy, insects don't fall under the same provisions that vertebrates do. And so, and you can imagine what the impact would be especially on a lot of these genetics labs that study fruit flies, where, you know, they're killing them by the tens of thousands that, you know, it would be a big problem if they had to do a ton of paperwork for each fly. [audience laughter] Do I feel guilty about it? Some, Argentine ants I've pretty much gotten over it. I'm not, I don't feel so guilty about killing Argentine ants any more. I feel like it's probably a good thing to diminish the number of them that are outside in the world. - [Annalee] They are an invasive species. - They are an invasive species, yeah, and they really hammer ecosystems so we should normally have like two dozen native species of ants around here, and you know, Argentine ants just eliminate all of them. But there are other ant species that I'm a little bit more, I don't know, that I feel a little bit more guilty about that. So, like harvester ants. These are seed harvester ants, they go out in the world, they collect seeds, and they bring them back to their colony. You see them frequently in deserts. They form these big midden piles around their nest entrances. And they're super cute ants. You can put them in like, if you have them in a jar with, like, a bunch of dirt, they'll separate the pebbles from the dust and pile them all up on one side. And they'll dig in the dust like little dogs. They're adorable. [audience laughter] And so, you know, I feel a little bit more guilty about experiments where we're going through large numbers of harvester ants. - [Fourth Audience Member] So I think I've heard about solitary bees, especially wild bees. And I was wondering if you knew much about why those bees are solitary? I guess it might have to do with different strategy for them surviving. And then also if there are example of ants that are solitary and what differentiates them from the more social ants. - Right, yeah, so that's an interesting question. Yeah, so that's exactly right. So, bees and wasps show the full range of social complexity. Everything from solitary to eusocial and everything in between. Like an example, something that's in between are bumble bees. So bumble bees, a colony starts from an overwintered mated queen, so she starts a colony by herself. She starts producing some daughters. Those daughters are the workers. And the colony grows and grows and grows. And at the end of the year, you know, everybody dies and the only bees, the only members of that colony that survive to the next year are the newly produced queens, right? And so they're like an annual plant where each generation the colony starts anew. Yeah, there are, and so, there are hundreds, probably thousands of species of solitary bees. And these are all around us. You look at flowers, you might often mistake them for a fly. Sometimes they're very small. Sometimes they're brilliant green, and very spectacular. And they're really important pollinators. Like the honey bee that we're more familiar with, they do, they don't attain the large population sizes the honey bees do, but they're very important. Especially in lots of natural areas for pollinating plants. Ants are all eusocial. There are no solitary ants. There are not even any like semi-social or sub-social ants. So all ants, and all termites have this really sophisticated social structure, eusociality. - But there are some ant colonies that are much smaller, right? - That's right. - Very low population. - And so there are ant colonies that are eusocial, but not nearly as sophisticated as some of the like Argentine ants or leafcutter ants or some of these that we're more familiar with. So there are ants that have colony sizes of a dozen to 20 individuals, and they don't have a fixed queen caste. So they have more of a reproductive dominance hierarchy. And so, you know, if the reproductive individual, the queen, dies, then others can assume that position. So they're, like in Argentine ants, workers are all anatomically sterile. Even if the queen dies, they will not be able to reproduce. But in other ant species, that's not true. - [Fifth Audience Member] I have two bee questions. So one is, how are the bees doing? For a while I was hearing a lot about colony collapse and sort of, we're gonna have the apocalypse because nothing's pollinating, and how are we doing with that? And then the other one is, I read something about anarchist bee hives evolving where they didn't have queens, and I'm interested in that. [laughter] - Yeah, so, colony collapse disorder is a problem for bees. And bees, and it's still a problem. And bees have lots of other problems as well. There's varroa destructor, which is a mite, and the mite itself is bad for the bees. And the mite also transmits diseases that are bad for bees like deformed wing virus, a viral disease. And there are lots of other diseases that bees have. And so there are still a lot of annual mortality on the order of a quarter to a third of hives die each year, but the bee keeping operations are pretty good about replenishing those lost hives, and so, I think, I wouldn't say that the apocalypse, the bee apocalypse is near, but certainly the way that we are managing honey bees, especially for pollination, isn't healthy for the bees. They're packed together in close quarters in enormously large numbers. Which are the perfect situations for diseases to originate and spread. They're being moved around frequently over large distances and subjected to thermal and environmental stress, feeding on diets that are unnatural or that are not diverse. And so there are lots of things about the way we manage bees that exacerbate this disease problem. And so I think there could be continuing, or worse problems in the future. Oh, and then the anarchist bees, right. So I've heard about the anarchist bees. I don't know too much about the details of it. But these are bees that have, where, I don't think individuals are reproducing willy nilly, but they don't have the sort of, the typical single queen who's doing almost all of their reproduction and workers who are doing virtually none of it. There is a lot more conflict among, many more individuals can potentially reproduce, and this produces conflict among the individuals about who should be reproducing, or and it produces behaviors where individuals try and police the reproduction of others by eating their eggs, for example, or exhibiting behaviors towards them to try and reduce their egg laying. And so it's a interesting model system for the structure and function of these societies. - Okay, let's take just these two last questions. Sorry. You can ask Neil other stuff. I bet he'll stick around. - [Neil] I'll be around. - Mine's a proxy question. - [Seventh Audience Member] He was going to ask the question but I can't stand up and walk over there. So it's a choose your adventure question, or two parts. I've read of somebody who was capturing and archiving of Africanized bees in the Los Angeles area and two, I'm still just baffled that bees that were at our place in Berkley which was very standing soil, there were in my car, they were in our bedroom, if you block the wall, they were gonna go over the ceiling. They never left the bedroom. There was no food in the bedroom. There was no water in the bedroom. - [Sixth Audience Member] Oh sorry, the ants, yeah. - [Seventh Audience Member] What did those ants want? - Oh right. - [Seventh Audience Member] Argentine ants, you know, by the thousands, in the bedroom. Never walked to the kitchen, never went anywhere else in the apartment. - [Sixth Audience Member] They'd just walk past, they'd walk right by, like, food, and go to-- - [Seventh Audience Member] I'm just fascinated by what they wanted. - Yeah, me too. [audience laughter] - [Annalee] So the question is what do Argentine ants want, why do they keep coming to our houses even though there's no food or anything for them? - Right, okay, so the first question about the Africanized bees in Los Angeles. I'm not familiar with that particular example, but, the Africanized bees can be kept in a managed setting. They're not ideal, because they're more aggressive, right? So you're more likely to get stung, and stung a lot. They're more likely to abscond, so they're more likely to pack up and leave your hive box. And that reduces the probability of your hive surviving because of the population number's halved or really reduced. Yeah, but I'm not familiar with this particular case. But I'm sure that there are lots of people who are bee keepers in Southern California who think they're keeping non-Africanized bees and they may actually be Africanized. And it's a continuum also, right? You can be, you know, the extend of hybridization, or the extent, the amount of the genome that is descended from the African subspecies, you know, can vary between zero and 100, right? And so, and all the numbers in between. - [Seventh Audience Member] It was someone specifically who, you would call them and say, oh my God, I have Africanized bees, and they would come out and collect them and the hive. - Oh right. - [Seventh Audience Member] For their own purposes. - Oh yeah, so that happens here in the Bay Area too, not necessarily for Africanized bees, but there is a sort of like watch list or something, where, you know, if you have a swarm that's shown up in your yard, say, you can alert this network and there are people who will, you know, come out, and you know, knock them into a cardboard box and stick 'em in a hive, and it's an easy way to establish a hive in your yard. You know, if you wanted to buy that, you would be spending 100 bucks or something for just the bees. Right, and into the Argentine ants. The Argentine ants, like, what do they want? I mean, I think they want the same things we want. It's, they're looking for shelter. They're looking for food. They're looking for moisture. They're really sensitive to drying out. And so they'll, when they are the worst inside people's houses are when it's really dry. During the summer they come inside looking for moisture. And then when it's really wet. When their colonies, which are fairly superficial, when they get flooded, they'll come inside, and relocate everybody else with them. But also, we're just living in a sea of Argentine ants too. And so it may be that your house is just perched in the middle of colony that extends over your entire block, and they just happened to be passing through, and you know, your home is an object in their environment. [audience laughter] - They don't respect property. [laughter] - [Eighth Audience Member] Hi, thank you. You talked about a division of labor among ants, and I wanted to know if there are any, if an ant steps out of line, are there any punishments, like, how does the colony maintain order? - Yeah, so that's like a classic question, evolutionary question in behavioral ecology. You know, so in societies, what, you know how do you, so there's a term for that is freeloader. How do you control freeloaders? You know, individuals that consume resources disproportionate to their contribution to the society. In some of these, you know, like in Argentine ant colonies, I don't know if there are mechanisms. I've never, I can't think of having seen any evidence of there a mechanism that keeps a worker in line. These are enormous colonies though that have, you know, hundreds or thousands of ants at a small scale, or millions, or billions at a slightly larger scale. But within other social, other societies, there are mechanisms such as the one I alluded to before with the anarchist bees. Where workers will police the behaviors of other individuals, especially regarding reproduction. And so ants, bees, and wasps are all in the order of Hymenoptera, and they have a weird, they all share a weird genetic system in that unfertilized eggs can become males. That's where males come from, actually. And so even workers who have not mated can still lay eggs and produce males. And so in some cases, workers will start doing this, dumping male eggs around in the hive, and other workers come along and are like, you know, killing those, eating those eggs to kill them or get rid of them, and then punishing the workers behaviorally by exhibiting overagression towards them. And we see this in other societies as well. In terms of, you know, making sure everybody is doing their task as much as they should? I don't know if there is as much evidence of that, of you know, them keeping an eye on who, are you foraging enough? Are you excavating the colony enough or not? I think that probably, you know, gets worked out by natural selection, you know? If there are, you know, if there's a colony that has individuals that are not working in some way as hard as they should, and there's a, and this has some sort of genetic basis to it, then, you know, those colonies will not faire as well in competition with other colonies that have a much more optimized work force. Right, and so over evolutionary time spans, those sorts of behaviors should be selected out. You would expect them to be selected out. So, yeah. - I just had one final question on that tip, which is, isn't there a phenomenon called lazy ants? Where there's just kind of ants that are kind of sitting around waiting to be deployed? - That's right, yeah, most ants are really, really, really lazy. And we see this, like in our ant colonies. You look at them and the vast majority of ants are just standing there. And you can come back the next day, and lots of them are still just standing there in the same place. [audience laughter] - Are these, are they sleeping? Or what are they doing? - I think the jury is still out. There has been some work on this in other species of ants and there are multiple hypotheses that various groups are testing to explain this. One is that they could be a reserve force that are only mobilized under certain conditions like a sudden pulse of a food resource, or the appearance of an enemy on your territory. It could be a developmental stage. These could be younger ants that are just waiting for their exoskeleton to harden. But yeah, I mean, it is certainly true that ants are usually doing not much. [audience laughter] - Well thank you so much for joining us. - Oh yeah. - This is Neil Tsutsui, everybody. [applause] You should check out his work. And also thanks to Eli's Mile High Club for providing the space, and Ars Technica Live will be back here next month, June 13 and my normal cohost, Cyrus Farivar, will be back. And we will be doing something unusual. He and I will be interviewing each other about his new book, which is a history of privacy and surveillance law in the United States. It's super interesting. And then he's gonna interview me about my book, which is actually fiction about the future of patent law. So we'll be talking about law, we'll be freaking out, it's gonna be awesome. There will be no ants, though. So hopefully-- - They're still here. - Yeah, they are still here. [laughter] The Dracula ants beneath our feet. - Great, thanks so much. - Yeah, thank you. [applause]