Vampire Bat
For a species that has inspired some of the best horror films in history — and, unfortunately, the Twilight series — vampire bats themselves are kind of a letdown. Contrary to what you've heard, the South American bats don't actually want to suck your blood. First off, vampire bats rarely attack people, preferring sleeping cattle and horses. They're not blood suckers either — they feed by using razor sharp teeth to open a patch of skin on their victims, before lapping up the plasma that leaks out. (The vampire bat's saliva contains chemicals that keep the wound from clotting, which has led some scientists to explore the bats as potential stroke treatments.) But don't think vampire bats are completely harmless — the messy, blood-to-blood transfer during feeding can spread nasty infectious diseases. And they're sneaky, too — like a heat-seeking missile, vampire bats use infrared radiation to find their prey.