New research has shown that vampire bats form social bonds by sharing freshly drained blood with unfamiliar members of their roost. It might sound desperately gross, but this behavior is showing scientists that vampire bats are incredibly prosocial animals.

"Food sharing in vampire bats is like how a lot of birds regurgitate food for their offspring. But what's special with vampire bats is they do this for other adults, eventually even with some previous strangers," Gerald Carter, lead author of the new study and assistant professor of evolution, ecology, and organismal biology at Ohio State University, said in a statement.