Life in the scorching hot Sahara Desert is no problem for an ant that has evolved an effective and stylish heat-repellant system, new research finds.
Saharan silver ants grow flashy body hairs that cause total internal reflection of light, which is a technique also used in manmade fiber optics. New findings about the cool system, published in the journal PLOS ONE, also report a scientific first.
Top 10 Hardest Working Animals Never Take a Holiday: Photos
This is "the first time that total internal reflection is shown to determine the color of an organism," Serge Aron of the Free University of Brussels said in a press release. As the name of the ants suggest, that color is glittery silver.
Aron and his team used a Scanning Electron Microscope to investigate the ant's hairs, watching what happens when incoming light hits them. They also compared normal hairy ants with some that had been shaved with a tiny scalpel blade to measure how light was reflected and how fast the ants heated up under simulated sunlight.
They found that the hairy ants were almost 10 times more reflective than the shaved ones, and were able to stay up to 35 degrees Fahrenheit cooler under simulated sunlight.
Video: 5 Incredible Insect Superpowers
The high-powered microscope revealed that each of the ant's hairs has a corrugated surface and a triangular cross-section. Like a prism, the hairs can then reflect light, such that the light rays entering each hair undergo total internal reflection, bouncing back off the bottom plane of the hair instead of transmitting through it.
The mirror effect gives the ant its bright silver sheen, likely provides some camouflage, aids in ant communications, and reduces heat absorption from sunlight. The latter prevents the ant from overheating.
While many Sahara Desert insects and animals come out at night to avoid daytime temperatures, the Saharan silver ant has no such fears.
Human Societies Starting to Resemble Ant Colonies
Aron, lead author Quentin Willot and their colleagues wrote: "Workers come out from the nest during the hottest midday period, when temperatures exceed 50°C (122 degrees Fahrenheit), to scavenge corpses of heat-stricken animals."
"By restricting foraging activity to the hottest period of the day," the researchers continued, "the ants minimize the chances of encountering their most frequent predator - a lizard that ceases all activities when the temperature becomes unbearable."
In addition to their silvery hairs, the ants are equipped with legs that are much longer than those of other ants. The long limbs keep their bodies away from the hot surface. They also allow the ants to run very fast, which helps them stay cool by convection.