Up north where there are very few types of snails that can survive the winter, they are like gold. They still breed very easily, but they are not to easy to get a hold of. The distributor limited us to only 50/week.
I have some that I collected from the Canadian border. They are like rabbits in my tanks. Get hold of some and then give them a tank of their own or where they won't be a fish snack. They reproduce every thirty days in a well fed tank.