Those are the kind of snakes that are dangerous to people. But in most cases snakes are afraid of people and will only bite if surprised by the sudden appearance of a person. Some poisonous snakes, like the Coral snake, have fangs that curve back to hold prey. Snakes don't have arms or legs. They move forward by tightening and relaxing muscles and pushing against rocks or sticks on the ground.
Some snakes move by side winding.
Side winding is when a snake throws and loops itself to get across hot desert sand. The sand is usually too hot for snakes to move on and the side winding movement reduces the amount of times a snake touches the ground. All snakes are carnivores but some snakes only eat eggs. Since egg-eating snakes eat only eggs, they have very elastic skin so that they can eat eggs larger than their heads. Egg-eating snakes have special teeth used to break open eggs.