This is the form of motion probably most familiar to people as the classic snake movement and also the most classic snake tracks. In lateral undulation, waves of muscular motion travel down the length of the snake’s body towards the tail.
As they come in contact with an object - such as a stick, plant stem, stone or piece of uneven ground – the part of the body nearest that object exerts force against that object, and deforms locally around it.
As the snake pushes against multiple objects, the overall motion of the animal will be forward.
This form is most efficient in areas of bumpy ground.