Hermit crab problems

[Jessie J.]

Hi everyone. My hermit crabs have been having problems lately. I have four purple pincher crabs (Pinches, Jo-Jo, Tracy, and Karmin) that I recently moved from a 10-gallon terrarium to a 55-gallon long tank. They have a nice cave to hide in and live on eco-complete substrate. Two of them have molted already. They have lots of spare shells, and nothing has changed (not even decor) since their move to a bigger tank. The crabs are all about the same size, but one is a little bigger then all of the rest and one is a little smaller then all the rest; these two were inseparable crabs and loved to hang out together. There have been NO, absolutely No, issues with aggression- until now. Now the smallest crab (Pinchels) will try to eat crabs larger then himself and even made another crab bleed. And the largest crab (Jo-Jo) will try to eat other crabs. Is this "cannibalism" some sort of freaky mating attempt? I heard tortoises will sometimes draw blood when mating and bite the shells of their partner. I sexed the crabs before and as far as I know they are all boys (I don't see any gonopores, but it is my fist time). The crabs will turn over another crab and pinch at the claw if it's blocking the entrance of the shell. Is this crab trying to get the other one's shell? What is going on, and how do I stop it if they are going to hurt each other?
Thank you all.

Jessie

 

[FishGuest5123]

I’m afraid I only had 2 hermit crabs together and they never bothered each other. Wish I could help.

 

[Jessie J.]

They've simmered down a little but I'm still puzzled at to what they're doing.

 

[Austinbeith]

Has anyone ever used an alternative to shells for replacement hermit crab shells? I was just reading up on them and seems that they will try on most shell shaped things. I just have a vision of hermit crabs walking around with little lego blocks on their back.