Moving without legs
Snakes have no legs at all, but they move quite well without them. A
snake can go zig-zagging over the ground just about as fast as you can
walk.
Most snakes leave a wiggly trail when they crawl. They do this because
they curve their bodies into one S shape after another. The top, middle,
and bottom parts of the S push against the ground. This makes the snake
slide forward.
The sidewinder snake moves sideways. It folds itself up like a spring.
Then it stretches its head out as far as it can and lays it on the
ground. It pushes hard against
Green Python
(above) A green python uses its belly scales to help it move forward or
climb, (right) A sidewinder crawls by jumping along the ground sideways.
the ground and pulls the rest of its body alongside its head. Each time
the sidewinder pulls itself sideways, its body leaves the ground a
little way. So the sidewinder is really hopping along instead of
crawling along! Instead of leaving a wiggly trail, it leaves a trail
like a row of I’s.
Some snakes crawl on the large, flat scales of their undersides. Pythons
and rattlers and boas do this. They push the scales forward. The scales
dig into the ground. The snake then pulls its body up to the scales.
This makes it slide forward in a straight line.
It seems as if it would be hard to move without legs. But snakes do it
well.
Sidewinder Rattlesnake
