system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 How Snakes Move

I know they slither, but how exactly does slithering actually move them?
gpt
Snakes have four ways of moving around. Since they don’t have legs they use their muscles and their scales to do the “walking”.

Concertina method: this is when snakes bunch themselves up and then throw themselves forward.

Serpentine method: This motion is what most people think of when they think of snakes. Snakes will push off of any bump or other surface, rocks, trees, etc., to get going. They move in a wavey motion. They wouldn’t be able to move over slick surfaces like glass at all.

Sidewinding: This method is similar to an inchworm’s movement. The snake will lift the middle of its body up and then push it down forcing its head to move forward.

Rectilinear Method: This is a slow, creeping, straight movement. The snake uses some of the wide scales on its belly to grip the ground while pushing forward with the others.