In southwestern Africa, a strange phenomenon called “fairy circles” have been puzzling researchers for years. These mysterious bare circles that appear on the plain are quite unique, and move from point to point every 40 years. Poisonous plants, ants, and even toxic gasses have all been attributed to fairy circles, but until now, no one has known what causes the perfectly circular patches.
Norbert Juergens, a German scientist, has found that the rings are caused by sand termites, a very prevalent and industrious insect. The fairy circles are engineered by the termites to maintain a water supply deep below the ground. First, the termites eat the all the grass roots in a specific area, creating the patch. Then, the grass around it is nurtured with moisture provided by the termites. The bare earth has now become a rain trap, for there are no plants to absorb the moisture, which sinks below the surface for the insects to harvest.
(via BBC News)