Namibia's desert is dotted with thousands of mysterious bare circles

Across the Namib Desert, hundreds of thousands of near-perfect bare patches ring themselves with taller grass, spaced almost like a honeycomb. Local folklore blames dancing spirits; scientists have debated sand termites versus grasses competing so fiercely for scarce water that a bare gap forms at the centre. Decades after they were first studied, the exact cause is still disputed.

— Norbert Juergens, The Biological Underpinnings of Namib Desert Fairy Circles — Science, 2013