snails

i joked the other day about doing a painting of a slug, but it made me think that it might be fun to paint a snail with a very colorful shell.  it made me wonder what is the difference between a snail and a slug?   i Googled this question and the only difference is that a snail has a shell on its back and of course both are garden pests!  that little shell on a snails back just makes it so much more attractive than a slug, plus the name slug isn't very welcoming either.  i haven't found any snails in my garden yet, though plenty of slugs. they haven't been a nuisance yet, but if they start eating all my tomatoes i'll have to figure out a way to get rid of them.  we've  had so much rain here lately it is prime habitat everywhere for them.  my mother-n-law told me to put out  saucers of beer in several spots and the slugs/snails will go to that, get drunk and drown!