Do snakes stilt? NEED SERIOUS ANSWER?
The lack of limbs does not impede the movement of snakes, and they have developed several different modes of locomotion to traffic with particular environments. Unlike the gaits of limbed animals, which form a continuum, respectively mode of snake locomotion is discrete and distinct from the others, and transitions between modes are abrupt.
 Lateral undulation
See also: Lateral undulation
Lateral undulation is the sole mode of aquatic locomotion, and the most common mode of earthly locomotion. In this mode, the body of the snake alternately flexes to the left and right, resulting in a series of rearward-moving 'waves'. While this movement appears rapid, snakes hold been documented moving faster than two body-lengths per second, often much smaller amount. This mode of movement is similar to running in lizards of the same mass.
Terrestrial lateral undulation is the most common mode of environmental locomotion for most snake species. In this mode, the posteriorly moving waves push against contact points in the environment, such as rocks, twigs, irregularities in the soil, etc. Each of these environmental objects, contained by turn, generates a reaction force directed forward and towards the midline of the snake, resulting in forward thrust while the
Banded the deep snake, Laticauda sp.
lateral components cancel out. The speed of this movement depends upon the density of push-points in the environment, with a atmosphere density of about 8 along the snake's length being ideal. The tidal wave speed is precisely the same as the snake speed, and as a result, every point on the snake's body follows the path of the point ahead of it, allowing snakes to move through very dense shrubbery and small openings.
When swimming, the waves become larger as they move down the snake's body, and the wave travels backwards faster than the snake moves forwards. Thrust is generate by pushing their body against the water, resulting in the observed slip. In spite of overall similarities, studies show that the pattern of muscle activation is different within aquatic vs terrestrial lateral undulation, which justifies calling them separate modes. All snakes can laterally undulate forward (with backward-moving waves), but solely sea snakes have been observed reversing the shape, i.e. moving backwards via forward-traveling waves.
A Mojave rattlesnake (Crotalus scutulatus) sidewinding
See also: Sidewinding
Most often employed by colubroid snakes (colubrids, elapids, and vipers) when the snake must move in an environment which lacks any irregularities to push against (and which so renders lateral undulation impossible), such as a slick mud flat, or a sand dune. Sidewinding is a modified form of lateral undulation in which all of the body segments orient in one direction remain in contact with the ground, while the other segment are lifted up, resulting in a peculiar 'rolling' motion. This mode of locomotion overcomes the slippery nature of sand or mud by pushing rotten with only static portions on the body, thereby minimizing slipping. The static nature of the contact points can be shown from the tracks of a sidewinding snake, which show respectively belly scale imprint, without any smearing. This mode of locomotion have very low caloric cost, less than 1/3 of the cost for a lizard or snake to move the same distance. Contrary to popular beliefs, at hand is no evidence that sidewinding is associated with hot sand.
 Concertina locomotion
See also: Concertina movement
When push-points are absent, but there is not adequate space to use sidewinding because of lateral constraints, such as in tunnels, snakes rely on concertina locomotion. In this mode, the snake braces the posterior portion of its body against the tunnel wall while the front of the snake extends and straightens. The front portion then flexes and forms an anchor point, and the posterior is straightened and pulled forwards. This mode of locomotion is slow and very demanding, up to seven times the cost of laterally gently sloping over the same distance. This high cost is due to the repeated stops and starts of portions of the body as well as the necessity of using alive muscular effort to brace against the tunnel walls.
 Rectilinear locomotion
See also: Rectilinear locomotion
The slowest mode of snake locomotion is rectilinear locomotion, which is also the only one in which the snake does not requirement to bend its body laterally, though it may do so when turning. In this mode, the belly scales are lifted and pulled forward before individual placed down and the body pulled over them. Waves of movement and stasis pass poste