The Compound Heat Shield of the Saharan Silver Ant

THE Saharan silver ant (Cataglyphis bombycina) is one of the most heat-tolerant land animals known. When the midday Saharan sun forces the ant’s predators to seek shade, the ant makes brief forays from its burrow in search of food, which consists of other insects killed by the intense heat.

Consider: The silver ant’s assets include a compound heat shield made up of a covering of special hairs on the top and sides of its body and a hairless underside. The hairs, which give the ant a silvery sheen, are tiny tubes with a triangular cross section. Their two outward-facing surfaces have microscopic corrugations that run the length of the hair, while the inward-facing surface is smooth. This design serves two functions. First, it enables the hairs to reflect solar radiation in the visible and near-infrared ranges. Second, it helps the ant to dissipate body heat absorbed from the environment. Meanwhile, the ant’s hairless underside reflects radiation that is in the mid-infrared range and emanates from the desert floor.

The Saharan silver ant’s compound heat shield helps the insect to keep its body temperature below the maximum it can tolerate—128.5 degrees Fahrenheit (53.6°C). Inspired by that tiny creature, researchers are working to develop special coatings that enhance passive cooling—that is, cooling without the aid of fans or other devices.