Of the more than 2,700 different kinds of snakes in the world, only about 400 are venomous to some degree. All snakes are carnivorous. A snake's eyes appear cloudy several days before they shed their skin. Snakes have backbones, just like human beings. Their skeletal structure is composed of hundreds of vertebrae, with a pair of ribs to go along with each.
Snakes flick their tongues in order to pick up chemical signals from their surroundings.
Snakes do not have external ear openings.