Social Insects

The Rickshaw Stop is better known for hosting indie bands than ant researchers. Although tonight’s headliner falls in the latter category, the San Francisco club is packed, rapt audience members crammed cross-legged on the dance floor or in tight rows of folding chairs. I snag one of the last spots. All eyes turn to the man onstage, a man whose T-shirt reads “Eat Bugs,” a man who is clearly in his element.

Amid earnest expressions of amazement, surprise, and the occasional “Yuck!” or “Creepy!,” Neil Tsutsui spends the next half hour describing the stranger points of ant social behavior, many of which have been illuminated through his own research: ants fighting to the death, ants building global supercolonies, ants kidnapping other ants and raising the young as their own.

As he’s wrapping up, Tsutsui, a professor of arthropod behavior in the Department of Environmental Science, Policy, and Management, has one final message: the next time ants invade your home, take a closer look before you rush to exterminate them. By the sound of the applause, the crowd takes his words to heart.

This is Tsutsui’s first time at Nerd Nite SF, a monthly series with the charming slogan “Be there and be square,” but it’s certainly not his first time talking ants with the public. He was a guest on a 2012 episode of the podcast Radiolab and has presented at many events, including Oakland’s Ars Technica Live and the California Academy of Sciences’ weekly NightLife—live ants in tow.

At such gatherings, he and other members of his lab, including postdoctoral researcher Elizabeth Cash and PhD candidate Kelsey Scheckel, perform “aggression assays,” placing Argentine ants from different colonies in a petri dish and seeing what happens (spoiler: it’s not pretty). To demonstrate how ants use pheromones for navigation, they lay a trail of the chemicals through a maze on a sheet of paper and show viewers that the ants quickly follow it.

They also answer questions, most commonly “How do I get ants out of my home?” The answer, at least as a first step, is to wipe the trail the ants have been following with soap and water to remove the pheromones, says Cash, who studies the genetic basis of how Argentine ants—one of the world’s most damaging invasive species—produce and perceive pheromones and other important chemical signals.

Tsutsui considers outreach not merely fun but also central to his life’s work as a scientist and teacher. It’s an impulse with origins extending all the way back to his childhood in Flagstaff, Arizona, where he grew up alongside an expanse of forest. He’d spend his days there roaming free, chasing lizards and insects and exploring whatever else intrigued him, returning home by sunset.

Tsutsui now lives in El Cerrito and has three kids of his own. He says his work with social insects, and that of others in his lab, continues to be motivated by “a raw curiosity about the world around us.” Tsutsui and his 13 undergraduate, graduate, and postdoctoral researchers study ants and bees, in the lab and in the field, to better understand their behavior, communication, evolution, and relationship with the environment. This work has important real-world implications for conservation and pest control.

The lab’s public engagement, meanwhile, is intended to spark a similar sense of wonder—particularly in those who have been “partitioned off from unstructured natural experiences” of the sort that led Tsutsui to decide at a young age to pursue entomology and, ultimately, to devote his career to learning more about why social insects do the things they do.

“Our main goal is to use insects as a vehicle for generating enthusiasm about the natural world,” he says of the outreach. “Our hope is that once we engage people’s interest, they will be more motivated to do some exploration on their own and hopefully support or participate in conservation efforts on their own.”

There’s yet another reason to engage the public, and that’s to obtain scientific data from sources or in quantities that a single lab couldn’t access on its own. Tsutsui and his colleague Brian Fisher, a curator of entomology at the California Academy of Sciences, started their first such project with the help of a National Science Foundation (NSF) grant in 2016.

Following the happenstance discovery of an abundance of ultrarare Dracula ants in a colleague’s swimming pool, Tsutsui and Fisher wondered what else they could find. So they asked eager citizen scientists across California with access to a backyard swimming pool to commit to skimming the surface of the water once a month for bugs, then mailing the goods to the lab. “We wanted to engage people in nature, but we wanted to do it in a way that they’d become involved in the gathering of data,” Fisher says. “To us, that’s the most exciting part of science: the process.”

Their ambitious project ended up including 11 sites and generating so much data that they’re still picking through it—literally. By the time the one-year collection period concluded last summer, volunteers had amassed approximately 31,000 individual arthropods, all classified to the level of order, including 2,800 ant specimens, classified to genus.

A great number of those insects came from just one of the sites, a backyard swimming pool in forested Big Sur that was positively crawling with critters. It was skimmed each month by San Francisco nature photographer Julie Jaycox, a friend of the homeowner who says she volunteered after seeing a call for participants in Bay Nature magazine.

“I love ‘playing in the dirt,’ and this was about playing with bugs and water while also gathering info for someone who was interested in it,” Jaycox says. Having recently read about the rapid decline in insect populations worldwide, she also saw value in contributing to Tsutsui and Fisher’s project specifically.

Though her father was an entomologist who introduced his children to the study of insects when they were young, Jaycox had never before engaged in scientific research. But she took to it with aplomb. “If there were a lot of insects, it was about a three-hour job. I liked getting everything,” she says. “But I cheated. I like bumblebees. If there were live bumblebees, I’d always rescue them.”

After carefully cleaning the pool and the spa, then emptying the scupper and the vacuum, she’d dump the catch into a small tub containing about an inch and a half of alcohol for preservation. Then she’d drive this “big gooey mess” back to San Francisco and personally deliver it to Fisher at Cal Academy.

Tsutsui and Fisher are now analyzing their data and looking for trends, like seasonal variations or geographic distributions. They’ve already made at least one important finding, which is that pools with Argentine ants tended to contain fewer native ants than pools without them.

“Argentine ants are such superior competitors that native ants can’t coexist with them,” Tsutsui says. And when the native ants disappear, other species can too, such as California’s coastal horned lizards, which depend on native ant species to survive. For someone who’s been studying Argentine ants for 20 years, the displacement of natives wasn’t a huge surprise. But actually generating data that showed it—in our collective backyard, so to speak—was a testament to the power of citizen science.

“If you’re going to do one of these projects, you have to be clear with yourself about your goals,” Tsutsui says. There may be a trade-off between collecting the most rigorous data and ensuring ease of participation. “The pools project is a good example of that. It was labor-intensive for the participants, and it also resulted in high-quality data.”

On the other end of the spectrum is another experiment developed through the NSF grant, called ANT-Vasion, which is easier for more people to complete but less tightly controlled from a research standpoint. Participants test the ability of various household spices—turmeric, cinnamon, and others—to deter Argentine ants from reaching a bait. Anyone can download the instructions (and later submit results) at backyardbiodiversity.org.

Scheckel incorporates the experiment into a College of Natural Resources course for non– science majors called Insects and Human Society, which she helps teach as a graduate student instructor. “We actually have some interesting data that has come through,” she says. “It’s fun, and it’s something that people can put to use in their own homes.”

Scheckel and Cash both say they have long been keen to engage with the public as scientists—and are fortunate to have Tsutsui as their lab’s fearless leader. When Scheckel joined the lab as a first-year graduate student and started to grasp the role that citizen science could play in 21st-century conservation, it shifted the trajectory of her education and career. “I realized that I want to eventually move away from ‘hard science’ methodologies that take place tucked away in a lab and instead work out in the community, where I can interact with the public as an educator,” says Scheckel, who studies a species of kidnapper ant known to employ the young of other species as a captive workforce.

She now uses the smartphone app iNaturalist (a Cal Academy initiative originally developed as the master’s project of three graduate students at UC Berkeley’s School of Information in 2008) to access records identifying local populations of kidnapper ants. These records may be input by other researchers or by members of the general public and are available for anyone to view.

Unrelated to her dissertation, Scheckel and others in the lab also lead teams during citizen science “bioblitzes,” in which members of the public are invited to survey the biodiversity of a particular place during a 24-hour marathon, recording all observed species. Past events include the Save Mount Diablo Bioblitz and the Hopland Research and Extension Center Bioblitz. Scheckel further complements her academic pursuits by regularly participating in Cal Academy’s NightLife and volunteering at Bay Area school and community events organized by the nonprofit Community Resources for Science.

Engaging the public is not quite feasible in Cash’s work studying ant genetics from the lab bench. But she’s nonetheless dedicated to interpreting science and the natural world for nonexperts. “I tend to do outreach because I really enjoy sharing my passion about ant behavior and ant communication,” Cash says—especially when it comes to the notorious Argentine ant.

She and Tsutsui suspect that the insect’s success may be due in part to its pheromones—more specifically, a group of chemicals called cuticular hydrocarbons. “They’re basically waxes that these ants produce and then spread around on the surface of their exoskeleton,” Cash says. “[The ants are] coated in this waxy substance, and other ants use this blend of waxes to determine which social group the ant belongs to.”

Sensed through the antennae, these chemicals aid in communication and support a rich social structure. But Cash and Tsutsui hypothesize that the waxy coating might also be useful for preventing desiccation in drier environments, helping Argentine ants invade a wide variety of habitats—and homes—all around the world.

The pheromone trails, aggression assays, and other crowd-pleasing demonstrations she does at outreach events are her way of communicating what could otherwise be a highly complex, rather dry foray into ant biology. At the same time, they reinvigorate her own interest in her work.

“I’m excited about connecting with people about my research,” says Cash, who led insect-focused nature hikes in the desert while pursuing her PhD in biology at Arizona State University. “I hope to spark an interest in someone else about insects and how fascinating they can be, and how important they are in our environment.”

From citizen science to social events, it’s all vital to Tsutsui, a scientist for whom public outreach is an art. In addition to his research, teaching, and public speaking, he’s even active on the city of El Cerrito’s Environmental Quality Committee, and he serves as a member of the East Bay Regional Park District’s citizens’ advisory group. His passion makes an impression, whatever the context. One afternoon as I sat writing this story and reflecting on Nerd Nite, a lone Argentine ant appeared out of nowhere on my keyboard. Instead of instinctively flicking it away, I remembered his appeal and bent down for a closer look.

Visit the Tsutsui lab website for more images of the lab in action, or to learn more about their education and outreach activities.