Stories about vampires have been heard and talked about for centuries. It was said that vampires were the souls of the dead who stalked the country looking for victims to suck blood. These stories existed in Europe long before the blood-sucking South American vampire bat was known to people. In the 1700, explorers to South and Central America related stories about bats which sucked blood. These stories were exaggerated, and it was then that all vampires came to be thought of as bats.
Bats are the only mammals that can fly. They are small animals, not more than six to nine centimetres long. The vampire bat of tropical America lives on the blood of other animals and spends about half an hour each night feeding. Vampire bats do not really suck the blood through the puncture wounds made by their fangs; instead they lap it up from the small incision (cut) made by their razor-like front teeth. Their saliva contains an anti-clotting agent and the blood simply comes out while the victim continues to sleep. Although the amount of blood lost by the victim is usually small, there is a risk that this bat can transmit diseases such as rabies. A vampire needs about 30 gm of blood each night and it may take it from one or more animals. Vampires may also suck the blood of a sleeping man, horse, cow, dog or goat.
Because bats like to rest in dark caves and come out only at night, they are greatly feared by animals.