What Makes a Snake - Statistical Data Included

Ranger Rick, Jan, 2002 by Ellen Lambeth

It hisses. It slithers. It's covered in scales. Make no mistake . . . it's a snake!

Check out that green tree viper coming at you in the photo at left. Does it seem creepy to you? If so, do you know why? Maybe it's because, like all snakes, it slinks and doesn't blink. Or maybe it's that whole legless thing.

Probably, though, it's just a fear you have because you don't know snakes well enough. The more you understand snakes, the less scary they'll seem. These questions and answers might help.

ARE SNAKES SLIMY?

A snake's scaly body may look shiny, but it's dry--never slimy. The scales are nothing more than areas of extra-thick skin. They protect the body and give the snake its color and pattern (see photos at the bottom of the page).

You can see that some scales look rough and others look smooth. Some overlap and others don't. A few kinds of snakes even have weird scales, such as the "horns" on the horned viper above.

WHY DO SNAKES SHED THEIR SKIN?

Because skin wears out. Your skin is being replaced all the time, bit by tiny bit. But when a snake sheds, its skin is replaced all at once.

When the snake is ready to shed, it rubs its head until the old layer of skin splits open and starts to peel back (below). Then the snake will crawl completely out, sporting a bright new layer of skin.

WHAT ARE THE SMALLEST AND BIGGEST SNAKES?

There are more than 2,600 different kinds of snakes in the world. The smallest are the blind snakes, such as the one at left. As you can see, one of those could curl around your fingertip.

Other kinds of snakes are so huge, you'd never be able to lift one--even with your strongest friends helping! The giant below is an anaconda. The largest one ever found was about 38 feet (11.5 m) long and weighed about 350 pounds (158 kg).

ARE SNAKES DEAF?

Snakes don't have ears that are anything like yours. But snakes can hear--just not very well. A snake's body also can feel the vibrations of something moving along the ground nearby. For a snake, that's as good as hearing.

HOW WELL CAN SNAKES SEE?

Some snakes have better vision than others. Compare the eyes on the snakes shown on pages 22-23. The shedding kingsnake has eyes with round pupils, which help it see well during the day. The two vipers have cat-like eyes. Their pupils can open very wide for seeing better in the dark.

Certain snakes, such as the copperhead (above right), also can "see" with heat-sensing pits. Special nerves inside the pits pick up body heat from warm-blooded prey. The nerves then send messages to the snake's brain, where a picture of the prey is formed.

WHY DO SNAKES STICK OUT THEIR TONGUES?

All the better to smell you with, my dear! The snake can smell with its nostrils. But it can smell much better with the help of its forked tongue (above right). The tongue picks up tell-tale odors from the air. Then it brings them to openings on the roof of the mouth. These openings lead into a special smelling organ.

HOW DO SNAKES GET THEIR PREY?

Some snakes just grab it with their mouths and gulp it down. Their backward-pointing teeth help hold on to slippery or squirming victims. Some snakes inject venom into their prey through special teeth called fangs (see drawing). This kills the prey and makes it easier to eat. Other snakes coil around their prey and squeeze them to death. That's how the Galapagos snake below can lunch on that lizard.

Acting Like an Accordion

That's what this kingsnake is doing to climb up this tree. First it bunches up. Then, using its belly scales to hold on at its back end, it pushes the front end forward. Finally it holds on with the front end, pulls up the tail, and starts all over.

HOW DO SNAKES MOVE?

No legs? No matter! Snakes get around with the greatest of ease.

Some snakes can zig-zag across the ground at several miles per hour. Many can climb. Many can swim too. (Sea snakes even have paddle-shaped tails.) And a few can "swim" through the air from tree to tree! (For more about "flying" snakes, see pages 36-37 in the November 2001 issue of Ranger Rick.)

Wriggling This is the most common way to go. The snake moves forward by pushing against things in its path, first on one side of its body and then on the other.

Sidewinding To move across loose desert sand, a sidewinder crawls with parts of its body lifted off the ground. The head lifts up and the body follows in a kind of looping action.

Creeping To go slow in caterpillar fashion, a snake straightens out and lets its belly scales do the walking! The edges of the scales grab the ground (see close-up). While they hold on, the snake pulls its body forward.

Take a good look at the emerald tree boa below. More than a hundred back bones in the spine make it easy for the snake to bend and coil its body. And strong muscles help it hold its head in midair while hanging on by its tail end!

HOW DO SNAKES HAVE BABIES?

Some snakes lay leathery eggs, while others give birth to live young.

A few egg-laying moms protect their eggs, but most just lay 'em and leave 'em. At right, you can see a rough green snake just coming out of its egg.