In emergencies, fire ants get lots of grips to form rafts
Inside look at how insects make instant architecture shows the power of extreme grabbing
By Susan Milius
The first scan inside a tight ball of fire ants shows that crisscrossing grips and the absence of slackers makes living rescue rafts.
“Imagine if you had 100,000 people trying to build a raft within a few minutes,” says mechanical engineer David L. Hu of Georgia Institute of Technology in Atlanta. An individual ant isn’t an innately buoyant material for a raft. It’s slightly denser than water. But during floods, a writhing ball of about 100,000 Solenopsis invicta fire ants needs only two or three minutes to arrange itself into a raft that can float for months.