With the latest Batman movie ("The Dark Knight") slated to hit theaters in July, it got us to thinking about bats. There's no question about it, bats intrigue us. But why is that? What's so special about bats that inspired Bob Kane and Bill Finger to create the Batman character in the first place? Quite simply, it could be that bats just stand out in the animal world.

Think about it – bats are the only mammals that can fly. And if you're going to ask, "But what about those flying squirrels?" They don't fly; they glide. There's a difference. Right, so back to bats. They spend much of their lives hanging upside down in dark caves or other similar spaces. Most species are only active at night, dusk and dawn. Many bats have developed adaptations, like echolocation, that let them find their way (and their prey) in complete darkness. And, there's that whole vampire thing. All of this adds up to some pretty cool stuff. Now you're beginning to see what might have inspired Kane and Finger, right? Read on for more reasons why so many people are "batty" for bats.

Bat Basics
There are more than 1,000 bat species in the world, making them one of the most prevalent orders of mammals. In fact, more than a quarter of the total number of mammal species are species of bat. Bat species are divided into two suborders. Megachiroptera, also called flying foxes or fruit bats, are found primarily in Africa, Asia and Australia. They are easily recognized by their long muzzles. Most megachiroptera species are vegetarians, feeding on fruit, pollen and even leaves. The other suborder of bats is microchiroptera. These typically carnivorous bats (most feed on insects, but some eat birds, fish, frogs, lizards, mice and even other bats) are found all around the world. They are generally smaller than megachiroptera bats, and most have pushed-in snouts, like a pug-nosed dog.

Image courtesy Don Pfitzer/USFWS Big brown bat

Bats vary considerably in size and appearance. The smallest bat, the bumblebee bat, has a wingspan somewhere around 5 ½ to 6 inches. When its wings are folded, it's about the size of a bumblebee (hence the name). It weighs about 2 grams – about the weight of a dime. The largest bat, the Malayan flying fox, can have a wingspan as wide as 6 feet, and weighs up to 2 ½ pounds. Apart from their leathery wings, megachiroptera bats look a lot like other mammals, with large eyes, small ears and extended snouts. Most microchiroptera species, on the other hand, have a completely unique facial appearance, with wide, extended ears and peculiarly shaped nostrils. These odd features help the bats get around in the dark.

The Truth about Vampire Bats There are a few species of vampire bats, and they do feed on blood, but they are not bloodthirsty man-hunters. Vampire bats merely prick an animal or human and lap up the blood that flows out. A powerful anticoagulant in the bat's saliva keeps the blood from clotting, so it will continue to trickle out like a little blood fountain. Vampire bats only need about two tablespoons of blood per day to survive, so they never consume enough to kill their prey, which is usually limited to large animals such as cows.