Perhaps no other animal is more closely associated with Halloween than the vampire bat. Whereas most bats feed on fruit or flying insects, vampire bats feed almost exclusively on blood; of the three living species, only the common vampire bat feeds on the blood of mammals, the others only target birds.
Vampire bats usually live in colonies of 100 to 1000 individuals. They spend their days sleeping and only leave to feed once total darkness has set in. Though they will target wild mammals and even humans on rare occasions, common vampire bats prefer to feed on domestic horses and cattle.
Despite its gluttonous feeding habits, the tiny vampire bat never drinks enough blood to endanger a large mammal. In fact, it is common for them to return to the same host to feed every night, even defending it from other hungry vampire bats.