The reed snake is only about eight inches long. Credit: Zoosystematics and Evolution Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. Only around 600 of the nearly 4,000 known snake species are venomous. The recently discovered Guangxi reed snake ( Calamaria incredibilis ) in China is not one of those species, but its alternative defense mechanism is strange enough to keep most predators at bay. According to a study recently published in the journal Zoosystematics and Evolution by biologists at the Natural History Museum of Guangxi, C. incredibilis wields its wide, stubby tail like a second head to scare away potential threats. Researchers first spotted the Guangxi reed snake during a biodiversity study in China’s Huaping National Nature Reserve near the nation’s southern border with Vietnam. The mostly nocturnal, non-venomous serpent grows to about eight-inches-long, and is identifiable by its small brown scales and seven darker stripes.…