EVER WONDERED if vampires really suck blood from their victims?

KidsPost asked our expert on all things gross, Washington pediatrician Howard Bennett, to tackle this question just in time for Halloween. Since he's writing a book called "The (Gross) Facts of Life," he was delighted to tell us about vampires-- not the fakes ones from horror movies but the real vampire bats that fly at night.

There are more than 1,000 species of bats in the world, but only three of them feed on blood. They live in Central and South America.

Bats are nocturnal creatures: They sleep during the day and come out at night to feed. They live in caves, tree hollows and buildings. The common vampire bat has a six- to eight-inch wingspan and a body the size of an adult thumb.

Vampire bats don't actually suck blood; they prefer to lick it as if it were an ice cream cone. After making a tiny cut in an animal's skin, the bats lap up the blood with their tongues.

The common vampire bat feeds on horses, pigs and cows, while the other two species prefer birds. Although vampire bats occasionally bite humans, we are not on their standard menu.

Blood contains chemicals that cause it to clot. That's how a person stops bleeding. All blood-sucking animals have chemicals in their saliva that keep blood from clotting. The chemical in a vampire bat's blood is called draculin, which is an obvious nod to Count Dracula, the most famous vampire ever.

On a good night, a vampire bat will drink half its body weight in blood. If an 80-pound kid tried to do that, he would have to drink five gallons of liquid! However, since vampire bats are so small, they drain only a tablespoon of blood from their host.

Blood is made of solid elements such as red and white blood cells and a watery substance called plasma.

Because vampire bats ingest so much, they must eliminate excess water right away or they become too heavy to fly. Luckily, they have very efficient kidneys and start to pee while they are still eating!

When vampire bats return to the roost, they meet face to face. If one bat went unfed, another bat will often regurgitate (or throw up) blood to share. Would you do the same thing if your sister came home late for dinner one night?

Although the bite of a vampire bat is not itself dangerous, it can spread a serious disease called rabies. If you ever see or hear about someone being bitten by a bat, tell a grown-up. Unless, of course, that bat is a 4-year-old dressed up for Halloween. In that case, just offer a piece of candy.

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