Kathy McCollum, age 10, of Huntsville, Alabama, for her question:

Why do snails come out only at night?

The slowpoke snail has sensitive skin. It is a rough looking dark skin with lots of wavy ridges. When you touch it, it feels cool and moist and clammy, and this is the way it must stay. On a bright sunny day, the air would dry the moisture from a snail's clammy skin    and that would be the end of him. This is why he usually stays home during the day and comes out to feed at night.

If all goes well, a snail can expect to live about two years  ¬and during his lifetime he never crawls more than about six feet away from home. His favorite home is a corner of the garden, when low hanging leaves shade the ground and the grass stays moist with the morning dew, In such a place, he can crawl around during the daytime. But if he lives where the warm sun dries the air, he crawls into his shell and waits for darkness. After sunset, the air is leas likely to dry up his damp, sensitive skin.