Snakes slither by using their scales as friction hooks to latch onto rough surfaces and propel themselves. They also shift their weight around, concentrating it in a way that allows them to move. Some snakes may have individual muscle control over their scales that allows them to move rapidly.
Snakes have varying methods of travel depending on their surroundings. Terrestrial lateral undulation is the most commonly used means of transportation. With this mode of locomotion, the snake moves its posterior in waves, pressing against nearby objects such as rocks, twigs and irregularities in the ground. The snake's speed varies depending on the environment.
In areas without objects to push off, such as in a sandy desert, snakes use a technique called sidewinding. The snake alternates its body sections in an up and down motion, which causes the snake to roll in a strange, sideways manner. Sidewinding is similar to lateral undulation, except that the snake only pushes off with static contact points of the body.
Aquatic snakes swim through the water, making waves that grow larger as they pass the snake's body. The snake moves forward slower than the waves pass and the waves thrust them forward. Aquatic undulation differs from terrestrial undulation, as the muscles activate differently. All snakes can undulate forward through water, but only sea snakes are capable of undulating in reverse.