As if you needed another reason to avoid bats this Halloween. Scientists have finally solved the mystery of where the SARS pandemic of the early 2000s originated: everyone's favorite flying mammal.

Normally, bats aren't normally much of a threat to humans (vampires in disguise notwithstanding). But when they carry diseases, all bets are off. The creatures have been linked to rabies, histoplasmosis, Ebola—and now SARS, the relatively new disease that was viewed ten years ago as possible apocalypse material. SARS, whose name stands for severe acute respiratory syndrome, was identified in 2003 after an outbreak began a few months earlier in Hong Kong. The disease spread easily between humans and during its height infected 8,094 people across the globe, 774 of whom died.

Although SARS has been thought to be linked to bats for a long time, a team of researchers was only recently able to isolate the virus to Chinese horseshoe bats, a species that often finds itself in close proximity to Chinese humans. And other species belonging to the horseshoe bat family share habitats with humans pretty much everywhere else.

Happy Halloween!

[image via AP, of Newt the Rodriguez fruit bat, who as far as we know is perfectly harmless]