They live everywhere except by the North and South poles. Snakes have long, thin cylinder-shaped bodies that are covered with scales. Each snake has a distinctive pattern on its scales and some are brightly colored. Snakes have a special slender, forked tongue that can taste smells by bringing smells from the air to the Jacobson's organ inside the mouth. They also have a special opening in their lips so their tongue can flick in and out of their mouth without them having to open their mouth.
Most snakes have jaws that can open wider than their heads so that they can swallow larger prey.
Snakes don't have eyelids or ears. Their eyes are covered by a see-through scale that is shed when they shed their skin, and they can't hear at all. They sense the approach of animals because they can detect low frequency vibrations in the ground through the bones in their lower jaw. Some snakes, such as Pit vipers, have heat sensors that can detect warm blooded animals nearby. Some snakes such as Pythons, Anacondas and Boa Constrictors kill prey by constriction.