The scorching heat of the hottest desert in the world seems “insignificant” to the Sahara silver ants.
A recent study has discovered that the heat of the Sahara Desert is not a problem for a species of ant that has developed an incredibly effective and stylish thermal resistance system.
Known as the Sahara silver ant (scientific name: Cataglyphis bombycina), this species boasts a shiny coat that reflects light completely, resembling a prism—a technique also utilized in artificial optical fibers.
The hairs on the back of the Sahara silver ant are responsible for their coloration. (Photo: P. Landmann, Willot et al).
“This is the first time internal reflection has been demonstrated to determine the coloration of an organism,” said Dr. Serge Aron from the Free University of Brussels.
True to its name, this coloration is a shimmering silver.
Dr. Aron and his team used a scanning electron microscope to study the ants’ hairs, observing what happens when sunlight strikes them.
They also compared normal ants with those that had their hairs shaved off to assess how light reflected off them and how quickly the ants heated up under simulated sunlight.
They found that normal ants could reflect light ten times more effectively than those that had been shaved and could keep their bodies up to 2oC cooler under simulated sunlight.
Scanning electron microscope image of the hairs on the Sahara silver ant’s body.
The high-resolution microscope revealed that each hair of the ant has a wavy surface and a triangular cross-section. Like a prism, the hairs in the layer can reflect light; rays striking each hair undergo complete internal reflection, bouncing off the hairs instead of passing through them.
This mirror effect allows the ants to maintain their silver sheen, aiding in camouflage, facilitating communication among ants, and reducing heat absorption from sunlight, ultimately protecting them from burning.
While many insects and animals in the Sahara Desert must venture out at night to avoid the harsh sunlight, Sahara silver ants can thrive during the day. They possess no fear of the heat like other species.
The special ‘hair’ with a metallic sheen covers the entire head of the Sahara silver ant.
“These ants leave their nests during the hottest part of the day when temperatures exceed 50oC, scavenging the corpses of animals that have died from the heat,” the researchers wrote in a report published in the journal PLoS ONE.
“By limiting their foraging activities to the hottest times of day, these ants minimize their chances of being spotted by predators. A lizard will cease all activity when temperatures become too hot.”
In addition to their silver hairs, this ant species has legs that are much longer compared to other ants. These long legs keep their bodies from touching the hot ground and allow the ants to run quickly to cooler spots after foraging.
