If their cargo gets wet, they will drop it and lose the day’s treasure
In Central America’s rain-drenched forests, leaf-cutting ants collect pieces of leaves on which they grow fungi for food. But the rain can hit hard, especially for a small ant. When leaf-cutting ants sense an incoming shower, they hoof it back to their nests, says a study in the May Insectes Sociaux.
Researchers from Argentina, Mexico and Peru tested how one species of leaf-cutting ants, Atta cephalotes, in Costa Rica deals with rain. The scientists placed hollow boxes filled with wet cotton on ant trails in the forest. When A. cephalotes walked through the boxes, they experienced higher relative humidity, as if it were about to rain. In another experiment, the researchers poured water on plants beside the trail to simulate falling raindrops. Both situations caused the ants to scramble to their nest up to 30 percent faster than normal, from about 1.21 meters per minute to 1