Reddish-hued circular patches several feet in diameter can be found in the grasslands of Namibia, and also in northwestern Australia. They’ve been dubbed “fairy circles,” and scientists have long debated what causes them: termites or an ecological version of self-organizing, an idea developed by Alan Turing. Host Marco Werman speaks with Stephan Getzin of the University of Gottingen in Germany, who is now ready to discount the termite theory.