Scientists have puzzled over the origin of Namibia's fairy circles for nearly half a century. It boiled down to two main theories: either termites were responsible, or plants were somehow self-organizing. Now, researchers from the University of Göttingen, benefitting from two exceptionally good rainfall seasons in the Namib Desert, show that the grasses within the fairy circles died immediately after rainfall, but termite activity did not cause the bare patches. Instead, continuous soil-moisture measurements demonstrate that the grasses around the circles strongly depleted the water within the circles and thereby likely induced the death of the grasses inside the circles. The results were published in Perspectives in Plant Ecology, Evolution and Systematics. About 80-140 kilometers from the coast in the Namib, there are millions of fairy circles - circular gaps in the grassland, each a few meters wide, together forming a distinctive pattern across the whole landscape and visible for miles around. The researchers followed the sporadic rain events in several regions in this desert and examined the grasses, their roots and shoots, and potential root damage induced by termites.