FAQ Can other animals live with hermit crabs?

Skyguyx5 asked:

Ok, I have seen a few posts about putting worms and other pets into the crabitat that I wanted to see what else we could put in there. Ive been thinking of putting another kind of animal in with my crabs because it will be more natural for them to be around other animals, like in the wild. So here are some that I came up with and some that Ive read about online. Thoughts and additions MORE than welcome!

Frogs (I think rottigirl has them in her tank????)
Millipedes- they seem to have almost the same needs as crabs?
Worms – ????
Fiddler crabs– you’d have to redo your tank for the fiddler crabs to have a lagoon type thing??? but will they take over the tank a bit?
While I think it would be fun to have other animals in there with the hermit crabs, I don’t want the other animal to be a hunter of hermit crabs, or the hunted… lol What else lives peacefully among hermit crabs in the wild?

LolaGranola answered:

Generally a bad idea because it’s a closed system. Hermit crabs go dormant during a molt and are very vulnerable to any kind of carnivore. A crab that would normally ‘move away’ to a new area to avoid other animals would be stuck in the tank which would provide an additional stress.