That's cool aye Ocean, didn't know that either. I had a couple that I got from Pick-a-pet in Papamoa Tauranga, they grew up really big in a fry tank of mine, then I put them one in my large discus display tank, survived a while then the discus bit through it's shell and ate it's insides out through the shell, was nasty getting it out (70cm deep tank too!), then the other one in the discus grow out tank slithered over the intake of the powerhead...thought it would be able to slither away, I was wrong, couple of things I learned there lol
As a side note, never saw them breed or any eggs etc, can they change sex does anyone know? I heard some snails can do this.