Vampire bats are the only mammals to subsist on blood alone. Their ancient ancestors might have eaten parasites and insects off larger animals until vampire bats began feeding directly from those animals themselves. So, how do these nocturnal creatures find their sustenance? And what animals do they most commonly target? Imran Razik follows the nighttime routine of a vampire bat as she hunts. Lesson by Imran Razik, directed by Sharon Colman.