Vampire bats are the only real vampires. There are three species of vampire bat, all of which live in South and Central America. These species feed on the blood of livestock, such as cattle, sheep, or pigs. Vampire bats are quite small and, although their bites leave distinctive marks, they don't usually kill the animals they feed on. But if the bat is carrying a disease, such as rabies, its bite can be fatal. Vampire bats are endangered because people are afraid of them, and tend to kill them as pests.