Sages through the ages have lauded ants as exemplars of industriousness, persistence and the virtues of collective effort. “Go to the ant, O sluggard; consider her ways, and be wise,” counsels Proverbs 6:6-8, yet most of us focus on extermination, not inspiration, when we find ourselves in the company of these social insects. Stomping, poisoning, drowning and burning are among the measures people turn to as ant antipathy verges on anti-ant pathology.
Meanwhile, the ants soldier on, an estimated 20 quadrillion in all — that’s 15 zeroes after the 20 — spread over some 15,000 known species on every continent except Antarctica. And raise those foam fingers high, because thanks to its diverse topography at the boundary of temperate and tropical zones, Arizona is America’s No. 1 ant state, with more than 300 species.
Although she studies social insects to better understand the relationship between individual actions and collective behaviors, Anna Dornhaus (pictured), a University of Arizona professor of ecology and evolutionary biology, doesn’t especially want ants in her house, either. But she points out that the ants we battle at home are non-native species she calls “tramp ants.” Poison these interlopers, and you’re also killing off natural-born Arizona ants — good ones that help control other pests — and other insects, including bees and butterflies.
According to her mother, Dornhaus was intrigued by bugs while growing up in Germany, but the scientist says she never planned to specialize in them. She worked in a University of Massachusetts lab with rhesus monkeys, and then her focus changed when she returned to Germany and joined a University of Würzburg department specializing in social insects. The department was headed by Bert Hölldobler, now an emeritus professor at Arizona State University, who, with renowned biologist Edward O. Wilson, co-authored The Ants, winner of the 1991 Pulitzer Prize in general nonfiction.
“It’s not that I picked social insects from a large menu of different organisms that I could have studied,” Dornhaus says. “There was a lot of serendipity. I just wanted to go back to Germany and study animal behavior. Würzburg was one of the two big places, and the other place studied guinea pigs. And I thought guinea pigs were boring. But social insects are incredibly fascinating. They have all of these intricate individual and social behaviors, yet you can fit them in the palm of your hand and also find them as soon as you leave your house.”
That’s certainly true in Arizona, where ant species have evolved strategies to survive the state’s extreme environments. Desert-dwelling harvester ants dig underground chambers 10 to 15 feet deep to escape the heat. But the harvesters also don’t like cold, especially for their larvae. So, in the morning, the ants grab larvae in their mandibles and haul thousands of them closer to the surface for warmth. As the day gets hotter, the larvae are carried back down into the burrow to keep cool.
If you think school pickups and drop-offs are a nightmare, consider the logistical challenges facing harvester ants. Colonies consist of as many as 100,000 ants, which means they have to efficiently navigate around each other to avoid gridlock. And beyond shuttling, feeding and cleaning the larvae, the ants have other jobs: They maintain and sometimes rebuild tunnels, and foragers need to venture out for food. How the ants figure out who does what, and when, remains a mystery.
Surprisingly, Dornhaus says, only 5 to 30 percent of ants ever leave the nest. And despite their reputation, ants aren’t always working. If you could look into the nest, you’d see many ants resting in their own personal spaces, called “special fidelity zones.” Some colony members are dubbed “lazy ants” and don’t do much of anything. But Dornhaus says these slackers tend to be young ants that aren’t yet mentally or physiologically capable of performing much work.
Despite the emphasis on the common good, Dornhaus says, ants have individual personalities. Some learn better, while select foragers take more risks and venture farther to find new food sources. To distinguish the individuals she studies, Dornhaus color-codes ants with paint. “Once you recognize individuals and observe them for a while, you see that they have quite different paths and interests,” she says.
Like moths to the flame and bees to nectar, the study of ants draws its naysayers. In 2009, the late Senator John McCain turned federal funding for ant research into a political sound bite, although he acknowledged being surprised and feeling “an element of pride” that “so much expertise concerning ants resided in the major universities in my state.”
Dornhaus sees value in fundamental research that expands our understanding of the world, but she also says ant studies yield “concrete economic applications” in fields such as computer networking.
“My broad argument is that ants and other social insects have collective strategies that have been optimized over millions of years,” she says. “Collective strategies are not necessarily intuitive for humans, so it’s actually hard for engineers to come up with these things. That’s why this inspiration from the natural world can be valuable: to understand how ants do things, then try to copy that in computing and other applications.”