LATERAL UNDULATION we just did a video on this type of movement!
I could watch this all day.
Only some of this is considered lateral undulation (i.e. the wider channels) in the more narrow channels the snakes are using concertina locomotion which involves alternately pulling the body into bends and then straightening out the body to move forward from the bends. Then the front part of the body comes to rest on the surface and the back part of the body is pulled up into bends and so on. The bends may push laterally against the sides of a tunnel or vertically against the ground to keep the body from slipping. Thus, static friction is critical to concertina locomotion. Concertina locomotion is used in crawling through tunnels or narrow passages and in climbing. In concertina locomotion, blocks of muscles are activated simultaneously, and unilaterally, in regions of bending and of static contact with the sides of a tunnel.
Snake raaace, snake raaaace, who’s gonna win the snake raaaaace~