All three species of living vampire bats occur in South and Central America. The three species are medium-seized, with adult wingspans of 320 to 350 mm and weights of about 40 grams. While they are larger than most of the bats of the temperate zones of the world, vampire bats are much smaller than Gigantic Flying Foxes, which weigh in at 1,500 g.

Evidence from proteins suggests that vampire bats have been around for 6 to 8 million years. Fossils of three other species reveal that several thousand years ago vampire bats were more widespread. They are known from Cuba and from as far north as West Virginia and the northern Califfornia, places where they no longer occur. With the exception of captive amimals, vampire bats have never been found outside of the New World.

Common Vampire Bats or "Desmodus rotundus."are the most widespread of vampires. They adapt well to captivity and often are exhibited in zoos. Hairy-legged Vampire Bats and White-winged Vampire Bats are less common and are less often caught by biologists.

While Common Vampire Bats may feed on the blood of mammals or birds, the White-winged Vampire Bat and the Hairy-legged Vampire Bat are thought to prefer bird blood.

Common Vampire Bats live together in structured societies or colonies that usually include one adult male with several females and their young. Like other bats, Common Vampires survive almost 20 years in the wild.