I have 3 snails in my 10g tank. 2 are bigger and one is tiny-maybe 1 mm in diameter. (I only pretend to know what a mm is. He's very little). So I was looking in there last night and see just the shell. I know the snail is not in there because I can see through it and tonight it's in the same place. Would one of the fish have eaten it? The snails have been in there for at least a couple of weeks now.