The vampire bat is the only mammal that flies and feeds entirely on blood. They are nocturnal, sleeping all day in a dark cave, hanging from the roofs in colonies of approximately one hundred. However, there have been caves discovered with thousands. One hundred bats can drink the blood of twenty-five cows in one year's time. Sleeping cattle and horses are the targets of these night time carnivores, with their razor-sharp teeth they are able to puncture the skin. They have a special heat sensor on its nose that tells the bat where the warm blood is flowing under the skin of the animal. They lap the blood with their tongues while the saliva keeps the blood from clotting. Each bat feeds for about thirty minutes. They never drink enough blood to harm the animal. Their bites however, often cause infection and disease. After feeding they hide out until some of the blood is digested because they are too full to fly. After the blood is digested and some of the water is absorbed, they are ready to fly back to their caves and roost during the day. Vampire bats prefer horses over cattle when they have a choice, and seem to prefer females over males for feeding. They often return to the same animal which they marked with urine and will fight off any other bats that attempt to feed on their personal host.
The hierarchy of the bat colony is unique because there are several males within the harem with one dominant male followed by other males in a sequence each breed a certain number of females, the female, however, can reject a male, and the bachelor males often attempt to breed with a female in a harem without success. The female produces only one egg at a time, and the male bat fertilizes the egg. The gestation period is about seven months. The baby bats feed on their mother's milk for the first three months of their lives. They clutch their mothers tightly and suckle even during flight.
There are three species of Vampire Bats the common vampire bat lives in the tropic areas of South America, Mexico and Central America it has a nose that is small and shaped like a leaf and an extra-long thumb. The Vampire Bat is the only one of the three that exists on the blood of livestock. The common vampire bat is a highly social animal and is polygamous the males will defend several groups of females. These bats also share their food and grooming. Bats will not survive for more than three days without feeding, hence the reason they often share food with other bats in their colony. The females are larger than the males in all three species of the vampire bat. The common vampire bat is considered more of a pest than the other two because it is a carrier of rabies. Most bats do not have rabies, the few that do, however, can transmit that disease through airborne transmission without any physical contact, bats that have rabies are often clumsy, unable to fly and become disoriented. It is wise not to handle bats or have them in one's living space. If one does appear in a person's sleeping area or in the children's room, it is wise to seek medical advice; it is possible to sleep through the bat's bite.
On the bright side, the saliva from the Vampire Bat has a unique property that has helped modern medicine with the new developed drug Desmoteplase, that is used as an anticoagulant. It has helped stroke victims with an increase in blood flow.
The other two vampire bats are The Hairy-Legged Vampire Bat and the White-Winged Vampire Bat both are parasite feeders with birds being their primary food source. All three species of vampire bats have the ability to run on the ground, a feat other bats are unable to do. They also can leap in different directions making it easy for them to move around at will. They have excellent eyesight as well as highly-developed senses of smell and hearing. While in flight, they have their mouths open for navigation as they emit echolocation signals. Vampire Bats prefer warm and humid climates and are often found in tropical and subtropical woodlands for foraging. They have also been sighted in the open grasslands around the tropical areas foraging. They prefer deep dark caves for roosting but also can be found in trees, abandoned building, mine shafts and old wells.