While ants can be annoying (see: showing up at your picnic table), humans generally regard them as good workers, which is how they’ve often been portrayed in folklore and fables such as Aesop’s “The Ants & the Grasshopper.” So it may come as a surprise that not all worker ants are performing at peak productivity; in fact, some research shows that up to 40% of worker ants in a colony may remain idle while other ants trudge on with their duties.
Biologists with the University of Arizona observing ant colonies in 2015 found that many of the ants seemed to slack while other ants performed chores. But in research published two years later by some of the same scientists, the team examined 20 ant colonies, marking some of the creatures with tiny paint drops and observing their movements. When the “lazy” ants were removed from their nest, life and work continued on more or less as before. But scientists discovered a major shift when actively working ants were whisked away; the once-idle ants stepped into their missing counterparts’ roles, assuming tasks that were going uncompleted. That encouraged scientists to view them not as lazy, but as part of a reserve force.
One theory for the behavior change is that keeping a team of workers on standby allows ant colonies to remain productive. A similar study in 2018 found that only 30% of workers in fire ant colonies dug tunnels, while other members of the nest waited nearby in a move that actually sped up work by preventing traffic jams in the narrow spaces. And some scientists believe that it’s possible certain ants are hard at work at nonvisible jobs that we humans just haven’t figured out how to recognize yet. Despite ants outnumbering humans 2.5 million to one, there’s much we don’t know about how they work together for their tiny, greater good.
Most ants have a defense mechanism of one kind or another. Some sting, like fire ants, while Formica archboldi ants spray acid onto potential predators. Few, however, can do what “yellow goo” ants can: explode. Found in Southeast Asia, Colobopsis explodens are tree-dwelling ants that build their nests high up in the canopies. As a last-ditch effort to protect their homes from invaders, Colobopsis ants apply pressure to their abdomen, bursting their bodies in a self-sacrifice that releases a sticky, odorous, and toxic substance. Researchers have known about exploding ants for at least 200 years, though the first documented research on their unique ability appeared around 1916. However, little is known about “yellow goo” ants, who spend their days foraging for food as one of 15 known species of exploding ants in South Asia.