Then, of course, are the three species of vampire bats. They live on the fresh blood of larger mammals. With their sharp incisors they bite or scrape the skin until the blood flows. They produce an anticoagulant to stop the blood from clotting and must often feed for an extended period of time. This is because blood is a relatively diluted food and it takes large amounts to get the nutrition that the bats need.
Vampire bats stomachs and kidneys rapidly separate the water from the rest of the blood.
In doing so, these bats can become engorged and unable to fly. Because of their peculiar feeding habits vampire bats can be carriers of blood-borne diseases, especially rabies. This can be passed on to other animals, livestock, or even humans. In many parts of the world there is still great prejudice toward bats. This attitude is so unfortunate not only for bats but for people as well.