In the 2008 film “Twilight,” a vampire describes the scent of blood as being “like a drug.” While in the world of fantasy, vampires may crave blood for reasons that are tinged with the erotic or infused with the demonic (such as in the 1922 movie “Nosferatu”), real life vampires actually exist in nature. Many real-life animals known as hematophages that sustain themselves on blood for a more practical reason — survival.
Some hematophages are well-known: For example, vampire bats in the subfamily Desmodontinae helped inspire the legendary monsters that bear their name and no one can forget blood-sucking mosquitoes and leeches. Many are also familiar with bloodsuckers that don’t target humans, such as lampreys (Petromyzontiformes), which live very deep in lakes and attach themselves to the sides of fishes with their strange, biting mouths.
