I used to have one. Outgrew its shell and found a home in a vertical plastic tube that was part of the gravel underlay system - therefore, could no longer move

I used to have one. Outgrew its shell and found a home in a vertical plastic tube that was part of the gravel underlay system - therefore, could no longer move around. I had to get a dozen other shells from the pet shop to give it something else to move into.