Oct. 23 - Scientists in Sweden have discovered that dung beetles not only feed on excrement produced by other animals, they use it to keep cool as well. Using thermal imaging cameras, the researchers found the beetles were significantly cooler when standing on their dung balls, a finding that suggests a previously undiscovered survival mechanism. Ben Gruber reports.
Ground temperatures in South Africa, the dung beetle's natural habitat, are amongst the highest on Earth. But Swedish scientists say the insect has developed an efficient system for cooling off. They say they observed that the beetle spent the hottest part of the day perched on its ball of dung. Using infrared camera vision the researchers found that when a beetle climbed on top of its dung ball its temperature dropped dramatically within 10 seconds. The moist balls stay cool through evaporative cooling - much like an air conditioner. To further test their theory, the scientists set up two arenas - one in a shaded area and the other in direct sunlight. They found that beetles in direct sunlight climbed on their balls seven times more often than their shaded counterparts. The researchers also painted silicone boots on the feet and legs of some of the beetles. Those sporting the boots climbed onto their balls less often. And when the temperature was at its peak, the beetles would wipe their faces. They are now conducting further experiments to see if the beetles are using regurgitated liquid to keep them cool as well. The researchers think that for a dung beetle - a combination of feces and vomit may just be the perfect recipe for staying cool under the desert sun.