Put yourself in the place of a harmless snake.
You’re just lying in the grass, minding your own business, when suddenly a
great big foot comes crashing down right next to your head. You take off
through the grass like greased lightning. In the distance someone screams, “Snake!”
Which one should be more afraid, the human or the snake?
A snake is simply a long, thin animal. It
does not have arms or legs. It crawls along the ground on its belly.
Snakes are reptiles. Like all reptiles, snakes are
cold-blooded. They can’t control their own body temperature, and so they have
to lie in the sun to get warm and in the shade to get cool.
WHERE DO SNAKES LIVE?
Snakes live almost everywhere in the world. They
live in grasslands, deserts, and rain forests. Some snakes live in water. There
are no snakes, however, in Ireland, Iceland, Antarctica, or New Zealand. There
are more than 2,500 species (kinds) of snakes.
HOW BIG ARE SNAKES?
The world’s smallest snake is about 5 inches (about
13 centimeters) long at full growth and weighs less than 0.1 ounce (less than 2
grams). The largest snakes are the anaconda and the reticulated python. They
both can grow as long as 33 feet (10 meters) and can weigh up to 550 pounds
(250 kilograms).
DO SNAKES HAVE BONES?
Like other reptiles, snakes are vertebrates—they
have a backbone. A snake’s long backbone is made up of small bones called
vertebrae. Snakes have between 100 and 400 vertebrae. Humans have just 32
vertebrae.
A snake’s jawbones are not attached to its skull.
They are linked together by muscles and stretchy tissues called ligaments. This
type of jaw lets a snake open its mouth wide and eat animals that are much
larger than its head!
A SNAKE’S SKIN
The dry outer layer of a snake’s skin is made
of scales. Scales give a snake its color. The color of some snakes lets them
blend into their surroundings and avoid being seen. Some poisonous snakes are
brightly colored to warn off enemies.
Snakes regularly shed their skin. First, a new layer of
skin forms underneath the old one. Then the snake loosens the skin around its
lips. Finally, the snake crawls out of its old skin. A brand new skin takes its
place.
SNAKE SENSES
Snakes don’t see or hear as well as other
animals. A snake has eyes but no eyelids. They have clear scales over their
eyes. Most snakes can see movement, but some snakes are blind.
Snakes do not have ears. They have bones in
their heads that can sense low sounds and vibrations.
Snakes have a great sense of smell. A snake
flicks out its forked (divided) tongue to collect scents. It doesn’t mean the
snake is hungry. The snake pulls its tongue in and sticks the forked tips into
a place in the roof of its mouth called Jacobson’s organ. This way of smelling
lets snakes find other snakes as well as prey (animals it hunts for
food).
Pit vipers, boas, and pythons have small pits on
their heads that can sense heat. These pits help a snake sense when a
warm-blooded animal is near.
POISONOUS SNAKES
Most snakes will not harm people. Garter
snakes and ribbon snakes are harmless snakes. But some snakes can be deadly.
They inject a poison called venom when they bite. They use venom to defend
themselves or to kill prey.
Poisonous snakes have two big, hollow teeth called
fangs. When they bite, the venom comes down through these fangs. Pit vipers
keep their fangs folded in their mouths until they are ready to strike.
Rattlesnakes are a well-known kind of pit viper. Cobras and coral snakes are
also very poisonous.
Spitting cobras do not have fangs. Instead, they
spit poison to defend themselves. They aim their venom at the eyes. The venom
can cause blindness.
Someone bitten by a poisonous snake should get
medical help immediately. Snake venom can be deadly.
BOAS AND PYTHONS
Boas and pythons are kinds of snakes known as
constrictors. These snakes have thick bodies and strong muscles. Instead of
biting, they wrap themselves around their prey and squeeze. They squeeze so
hard that the animal can’t breathe and dies.
HOW DO SNAKES MOVE?
Some snakes move by wiggling and squirming
forward. Some snakes make leaping, twisting movements called sidewinding.
Snakes that live in trees coil their tail
around a branch. Then they hook their neck into a higher part of the tree and
pull the rest of their body up behind them.
WHAT DO SNAKES EAT?
Snakes eat a variety of things: worms,
insects, lizards, small mammals, birds, and frogs. Some snakes, such as the
Australian bandy-bandy, feed only on other snakes. Other snakes like to eat the
eggs of other animals. An adult reticulated python eats larger prey, such as
wild pigs, monkeys, and small deer.
Snakes don’t chew their food. They swallow it
whole. Their teeth point backward, which helps to keep prey from escaping. Many
snakes begin to swallow their prey while it’s still alive. Others kill the
animals before eating them.
LIFE CYCLE OF A SNAKE
Most snakes lay eggs. Some sea snakes and snakes
that live in cold places give birth to live baby snakes.
Some snakes can begin reproducing at two years of
age. Others take slightly longer to mature. Snakes may live for as long as 20
to 30 years.
SNAKES AND PEOPLE
People in Asia and other places kill snakes
for meat. Some people make shoes, belts, purses, and other things out of
snakeskin. When people build houses and farms, the places where snakes live are
often destroyed.
Scientists and other experts fear that some snakes
could become endangered if the killing of snakes or the destruction of their habitat
(living places) continues. Some countries have laws against killing or selling
snakes for their skins or their meat.