Ants Act As Liquids And Solids

I’m fascinated by ants. I remember when I was a kid I’d toss a piece of bread on the ground and just wait for all the ants to swarm and cover the bread. The ants would climb on top of one another but it always seemed like there was order in the madness. Solo, they’d march along but together they were fluid.

Apparently, I am not alone with my love of ant mobs. A group of researchers from Georgia Tech probed the mechanical properties of fire ant aggregations by putting thousands of ants into a rheometer, a machine used to test the solid-like and liquid-like response of materials such as food, hand cream, or melted plastic.

“Ants seem to have an on/off switch in that they let go for sufficiently large applied forces,” says David Hu, an associate professor in the George W. Woodruff School of Mechanical Engineering. “Despite wanting to be together, they let go and behave like a fluid to prevent getting injured or killed.”

In this short video, Hu explains what happens when a mass of ants is faced with a big, bad penny.

You can read more about the wondrous world of ants via this article on Who knew we could learn so much from such little creatures?

Traci-bio-photo.jpgTraci Purdum is Chemical Processing’s senior digital editor and ant champion – as long as they aren’t hanging out in inappropriate places like her kitchen. You can email her at