The common vampire bat is a bloodsucking bat, and the species that people usually refer to with the informal term "vampire bat". They are famously associated with vampires.
The common vampire bat feeds exclusively on the blood of birds and mammals, so their bodies are specialized for sucking the blood of their prey. For example, they are unusually good at walking among bats, being able to move over ground in a hopping fashion by folding up their wings. That is because the weight of the blood they suck makes it difficult for them to fly away. Also, their sharp teeth allow them to bite without causing pain. After biting onto their prey, they lick up the blood with rapid tongue movements.
They are highly social animals, living in groups of 100 to 1000. They starve to death after 60 hours without food, so they participate in the altruistic behavior of sharing the blood they drank with those who couldn't obtain their own food.Japari Park, Lucky-san (Gokoku Area)Animal Introduction