I have hermit crabs in the tank. All but the one Bubbles (puffer) caught are VERY small. All are hiding in the rock. We got her a little over a week ago. We haven't really seen her eat a lot so we were getting worried. Got back from camping this morning and there's the empty shell. To answer your question. No we are not just feeding her hermit crabs. We have been putting krill in the tank also. And we got some garlic today to soke some shirmp in. To be honest, I'm just happy to know she ate something.