So I have had 3 hermit crabs in my tank for the past couple months. All of the sudden I look and see that I have empty shells. At the same time I notice this stuff on the bottom of the tank. Did they die off or could my emerald crabs have eaten them? I have only one left out of the 3. I ask about the emerald because i have seen one of them on top of the existing hermit a bunch of times. Oh I also did have a bunch of slightly larger shells for growth also but everything but the one that I have left is empty.

