Only 3 out of 1,300 species of bats drink blood, and only by scratching or pricking an animal, then lapping at the blood — not puncturing the neck and sucking it dry like a mythical vampire. Because of this blood drinking trait, these 3 bat species were named “vampire bats.” Clocking in at about the size and weight of 2 AA batteries, vampire bats aren’t very large, scary monsters–despite their slightly demonic little faces.