Silver ant hairs reflect sunlight, keeping Sahara dweller cool

Hairs on the Saharan silver ant help keep the insect kicking in scorching desert heat. The sophisticated heat-regulating properties of the ant hairs’ silvery sheen, reported June 18 in Science, could inspire materials that thermally shield objects in hot environments.

Previous research revealed that silver ants (Cataglyphis bombycina) are speedy sprinters and master navigators, traits that enable swift scavenging for insect corpses on sand that can reach 70° Celsius.

Rüdiger Wehner, an invertebrate neurobiologist at the University of Zurich, and colleagues ran lab tests on the ant’s hairs. As expected, the shiny tendrils adeptly reflected most wavelengths of sunlight. Yet the hairs are nearly transparent to mid-infrared radiation, which the ants emit as heat. That’s a sneakily good strategy: It ensures that when the ants overheat, they can find a relatively cool spot — perhaps atop a rock or plant that rises above the scalding desert surface — and quickly vent body heat.