The Saharan silver ant keeps cool by reflecting sunlight with its silver prism-like hairs. Photo by P. Landmann, Willot et al.

BRUSSELS, April 13 (UPI) -- The metalic sheen on the body of the Saharan silver ant is a result of the species' special hairs.

Scientists have previously credited the ants hairs with keeping it cool in the desert sun and giving the species its signature shine. But for the first time, scientists took an in-depth look at the hairs' optical properties.


Using a scanning electron microscope, researchers were able to reveal the unique design that offers the hairs their total reflectivity. Each hair's triangular cross-section and corrugated surface causes it to act like a prism, with sunlight reflected off the bottom side.

The total internal reflection ensures the hair doesn't absorb any heat and offers the ant's body effective thermoregulation.

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To measure the thermoreglatory properties offered by the hairs, scientists subjected a group of Saharan silver ants to simulated sunlight. Half of the ants were shaved, the other half not. The hairy ants remained 2 degrees Celsius cooler than their hairless peers.

In addition to an ability to withstand desert heat, the ant's prism-like hairs also offer the insect species its silvery metallic sheen.

Researchers shared their analysis in the journal PLOS ONE.

"The ability to reflect solar radiation by mean of total internal reflection is a novel adaptive mechanism in desert animals, which gives an efficient thermal protection against the intense solar radiation," Serge Aron, a researcher with the University Libre de Bruxelles, said in a news release. "To the best of our knowledge, this is also the first time that total internal reflection is shown to determine the color of an organism."

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