Ltshears [creativecommons license] via Wikimedia CommonsDesmodus rotundus is one of only three species of bats that feed exclusively on blood. Commonly called vampire bats, these nocturnal flying mammals have a body length of roughly 3 in and a wingspan up to 15 in. They usually weigh 20–50 g and live up to 12 years in the wild. Their short fur is grayish on the underside of the body and darker gray to brown on the back.
Fluent in Science