The vampire bats (Desmodus rotundus) have a wingspan of about 20cm and a body about the size of an adult's thumb. If not for their diet, people would pay little attention to these small mammals.
Staple diet - blood!
Vampire bats feed on the blood of large birds, cattle, horses, and pigs. Using their bladelike upper incisors, the bats make tiny cuts in the skin of a sleeping animal.
The bats' saliva contains a chemical that keeps the blood from clotting, allowing the bats to lap up the blood that oozes from the wound.
Another chemical in their saliva numbs the animal's skin and prevents them from waking.
Can die if do not get blood on regular basis
If vampire bats do not get their share of blood on a regular basis, they rapidly deteriorate and may be close to starvation within 2-3 days.
A vampire bat finds its prey with echolocation, smell, and sound.
In addition to flying, they can also scuttle along the ground with amazing speed and agility (covering up to 2.2 meters per second).