Well, I'm going to probably have babies. Since the smallest one is constantly all over the others. They are a weird snail to watch. They almost bury themselves in the gravel for about 6 hours and then move somewhere else. I better be carefully when I clean the tank so I don't bury them alive or crush them.
FYI - I added some Eco Complete substrate on top of the pond pebbles in my Assassin tank and they are much more active. I think they prefer I finer substrate; at least this is my observation.