I discovered one of mine eating one of my crypt plants I just paid $9 for at the fish store, so they are spending some time in "snail jail" until I figure out if I can keep them from eating my plants. I think it depends on what species you have if they will eat plants, and many of them look similar. Nerite snails are supposed to be better at controling algae and don't eat plants generally, but I don't think they look as neat.