Fire ants, those stinging pests that are all too familiar to Southerners, have gotten plenty of attention from scientists — but not from physicists.

Usually the issue is how to stop the spread of the most problematic of the different species, or figure out why the sting is so painful. But scientists at the Georgia Institute of Technology, including Zhongyang Liu and David Hu, were interested in the ways that a mass — or you might say, a mess — of fire ants can act like a fluid or a solid, depending on the situation. It’s the first time this duality had been observed in a group of living things.

In a presentation at a meeting of the American Physical Society last month the researchers showed video of the ants pouring out of a funnel, like some thick and wriggling syrup, and also springing back into a rough ball shape after being pressed down.

These images illustrated the findings of the more technical research, done with rheometers to measure the precise viscosity and elasticity of balls of ants under stress. The researchers found that in different situations the ants behaved differently.