It is a rare event that you catch a snail on the move. Most of the time they are still, either asleep or appearing to be so. This is partially because snails are mollusks, which is why they are slimy.
Snails need moisture to live, and if they dry out they will die. As a result, desert dwelling snails have developed many techniques for keeping their moisture intact.
One development they have is that they are nocturnal. During the day snails sleep in the protection of their shell, with their eyes actually inside of their heads. When they come out at night, they move very slowly and cautiously. Snails feed at night, munching on whatever vegetation they can find. They rely mostly on their sense of touch when finding food, because they cannot hear and have very poor eyesight.
When they are out of their shells, you can see part of their slimy bodies and eyes. Their eyes are actually on the ends of tentacles that come out of their head. If they feel threatened, they will draw their eyes into their head for protection. They can even withdraw one tentacle at a time if they want to.
Snails do not need to find mates, because they are hermaphrodites. Each snail produces about thirty eggs and places them underneath a stone for them to hatch. If the air gets particularly cold, the snail will bury itself underground for warmth.
Also, it produces a slimy gel that covers the opening of its shell, leaving only a very small hole that allows air to pass through. This slime is so think that a snail can crawl across the edge of a razor and not get hurt. As snails crawl, a trail of slime is left behind. This is a telling result of their often strange paths, usually traveling in circles. Snails can crawl up walls and even upside down because of the slime produced by their bodies.
Desert snails also have been known to use digging in as a defense mechanism, but for a different reason. Snails can sense when the air is particularly dry, and will burrow underground as a result.
Amazingly, they can hibernate there for three to four years until the climate becomes more suitable for them. Overall, snails have been known to live for up to fifteen years. No wonder snails are so sexy!