Vampire Bats Now Feasting on Human Blood

Human encroachment typically means bad news for a given species (recent examples include giraffes and cheetahs), but one mammal appears to be fighting back. Researchers say the hairy-legged vampire bat has adapted surprisingly fast from drinking the blood of birds to that of humans to survive, reports the Telegraph. In the journal Acta Chiropterologica, scientists report that that they extracted DNA from 15 samples of feces at a colony in Catimbau National Park in Brazil and discovered human blood in three of them. "We were quite surprised," says one researcher, per New Scientist. "They are adapting to their environment."

Vampire bats have evolved to process bird blood, which is higher in fat than mammalian blood. They've even been found to fast and starve when only pig and goat blood is available, but their main prey of guans and tinamous are dying off thanks to hunting and deforestation. The research team says it expects the bats feast at night, entering bedrooms through open windows and holes in roofs, and say it's time to monitor them for diseases they are known to carry, including rabies and hantavirus. For now, they're reaching out to nearby residents for more information on how, when, and where they're being bitten. (This man died of rabies in the US after a vampire bat bit him in the heel.)