What are they? Dung beetles – a.k.a. scarab beetles – are members of the 4,500-species Scarabaeidae family. These are typical insects with a head, thorax and abdomen. While the head has the brain, mouth and sense organs, and the thorax has the wings and legs, the abdomen houses the essential body organ of this story – the digestive system. About their diet. These beauties search out piles of animal excrement where they ball up some of the dung and roll it away. When they are far enough away to feel safe, they bury themselves and their dung ball and consume it underground. Ugh! So what's the problem? Other beetles try to steal their dung. When that happens and they try to escape, how do they know which way to run? They take off in a straight line following the polarized light of the Moon. When a team of researchers at the University of Lund in Sweden blocked their moonlight, the beetles ran around in circles. When the researchers filtered their moonlight through a polarizing filter that changed the direction of polarization by 90°, the beetles turned and ran off at a right angle. What's the news in this? Scientists have known for some time that desert ants and honeybees follow the polarity of Sun light in the daytime. Some even suggest that lizards, birds and fish may use polarized light to navigate. The novel element here is the dung beetle is the first animal confirmed in its use of polarized Moon light as a guide. Sources:
Agence France-Presse (AFP). Dung Beetle Uses Moonlight Compass. 2003 July 2 NewScientist.com news service, 18:32, 2002 July 03 Nature, Vol. 424, Pg. 33 |
