They curl themselves up in order to stay warm.
Snakes curl up when they are sleeping and resting. Snakes may also begin to curl before an attack. It is best to stay away from a snake if you are not sure what the behavior is.
to reduce heat loss
Most snakes curl up when they sleep, but not all snakes. Some snakes are arboreal, which means they live in trees. They curl up on a branch to go to sleep. Most other snakes, such as ball pythons, king snakes, and rat snakes seem to like a hiding place when they rest and you will often find them curled up under a rock or log or other out of the way place. However, there are certain very large snakes (think anacondas or Burmese pythons) that just seem to lay straight out in a line. Although I am not certain, I think you would find that these snakes don't have many natural predators so they don't need to hide themselves. Even these huge snakes will try to go to an out of the way place after they have eaten a huge meal, since they are vulnerable for a couple of days right after they have eaten.
to preserve heat by reducing exposed surface area
A few possible answers: Armadillo Millipede Snakes
you should put on a pfd and huddle with others or curl up in a ballyou should put on a PFD and Huddle with others or curl up in a ball.
all snakes can climb how do you think they get high up on trees.
Curl-up was created in 1951.
Koalas do smetimes curl up tightly when they sleep. They curl up in winter to keep warm.
A snake is cold blooded. It required the sun to heat up its body.
a curl up is when you do an exersize to sit up and then back down up.... and down.
a curl up is when you do an exersize to sit up and then back down up.... and down.