Vampire bats (desmodontidae) constitute a serious economic, veterinary and public health problem in Latin America, not only because they can transmit rabies and other diseases to domestic animals and to man, but also because their sole food is the blood of birds and mammals, including man: the vampire drinks about 20 cc of blood from its prey.
Because vampire bats are often rabid or spread diseases such as encephalomyelitis, they can cause the destruction of as many as one million cattle each year. It is estimated that these bats cause the destruction of US$ 1,250 million worth of livestock annually in Latin America.