How Fire Ants Form Rafts to Survive Floods


While reporting on severe flooding conditions in Greenville County, S.C. last week, news anchor Adrian Acosta nearly stepped into what he thought was a puddle of mud. On second look, he realized the dark mass was something else entirely—a giant mass of fire ants drifting over the water’s surface.

Curious about the phenomenon, Acosta sought answers. He discovered that, to weather floods, fire ant colonies employ an interesting survival technique: They can quickly create a makeshift raft out of their own bodies, experts explained to USA Today.

After gathering their eggs, the ants use their jaws, claws, and oily legs to join together, clumping into a flat, pancake-shaped mass. This formation allows them to float for days—or weeks—until they reach higher ground. However, it’s not like the insects on the raft’s top layer are surviving at the expense of the bottom ants. According to LiveScience, ants have a hard, water-repellant outer covering, which allows them to form an air pocket while submerged in water.

It’s a good thing Acosta did a double take: If you come in contact with a fire ant raft or break it apart, the ants will most likely crawl onto you. Considering that fire ants are infamous for their stinging bite, that’s probably not something you want to happen. However, if you do encounter an ant raft, you can use soap—which breaks up the surface tension of water—to send the hoard of potential pests to a watery grave.

Want to learn more? Check out the above footage from WSAV photojournalist Chris Murray, who captured the same phenomenon in S.C.'s Dorchester County.

[h/t Fox Carolina]