Metallic hair helps ants beat extreme desert heat
Hair is usually employed by the animal kingdom for insulation. Some famous examples include species with so much fur they’re named for it, like a woolly mammoth. This is only one side of the insulation story though, as Saharan silver ants prove hair’s utility in staying cool as well. This is important, as they often find themselves out looking for food in temperatures of up to 158º Fahrenheit.
The hair works in two ways, reflecting sunlight and helping remove heat from the ants’ bodies. The distinctive silver coloring of their tiny hairs acts like a layer of tin-foil, reflecting visible sunlight as well a near-infrared light when the ants venture outside. Aside from the color, the shape of the hairs help too. Rather than round shafts, each hair is shaped like a tall, triangular prism. They also have a hard bend in them, so that they don’t lay flush against the ant’s carapace. Instead, they leave a then layer of air that helps circulate air around each hair, helping to draw heat off of it, and therefore off the ant. It’s similar to heat sinks used in cooling computer components, only on an amazingly compact scale.
The combination of these two pieces of biological engineering make a huge difference. Properly hairy ants have their temperature reduced by as much as 50º F, which is good since the ants die at 128.48º F, leaving them a bit of a buffer when they go out searching for food. All together, this system allows the ants to actually take advantage of these extreme temperatures. Even though they only risk exposure for 10 minutes at a time, the environmental heat helps keep predators away. Since they’re the animal with the air-conditioning, it makes mid-day savaging much saver than dusk or at night, when most desert animals are more active.
Source: These ‘silver’ ants use special hairs to survive the harshest desert heat by Elahe Izadi, Speaking of Science
