HCA: Hermit Crab Association

One of my crabs was alone for a bit less than 2 months. I then introduced 3 more crabs, all of which were smaller. My original crab had just molted and was trying around for some new shells. While doing this, one of the new crabs took his old shell. My original crab seems to want that shell back. I witnessed him trying to steal it (as in trying to kill the new crab for the shell).

After that I isolated my original crab in fear that he would kill my new crab for the shell. How long should I isolate my original crab? Or is this something that can't be fixed (as in he'll always want the shell back)?

Just some other info: My new crab fits really well in the shell, yet my original crab does not at all (it's too small). Yet he still insists in going in it. I'm not sure if my original crab is happy in the shell he is in now, or if he still wants the other shell.

He has been isolated for about 5 days now.

I need to make a decision quick of whether to isolate him longer or put him with the other crabs. Due to family reasons, they are getting impatient with the two tanks. They are calling it "cruel" isolating one the of the crabs, I just don't want to wake up to a dead hermit crab.

The crabs have plenty of space to hide from others and are getting plenty of nutrients. About 3 to 4 inches of sand and eco earth is at the bottom, so just enough to dig in. The humidity and temperatures are perfect. They have the perfect environment, so I don't think any of the aggression is coming from tank/care issues.

Any tips and advice is very much appreciated

Thank you!

I suggest buying about 15 more turbo style unpainted and unpolished shells for your crabs to look around at (minimum three shell options per crab). Also make sure to be feeding them protein options like chicken each night because they may just be hungry for meat! Additionally, dunk them all as they independently arise from hiding in freshwater to eliminate crab on crab aggression as you mentioned and they will all share the same scent. If your crab just molted and you already moved him, I would leave him alone during this time where he is vulnerable and give him shells to chose from. These are social animals but it’s important to research or keep in mind the traumatizing trip they have up to our crabitats so sometimes 2-3 weeks will do good for the new hermies to acclimate. Remember to never dig up crabs because it can kill them.
Hope this helps!

agreeing with bugssnow&milly i would make sure to have at least three to five shells per crab
i would purchase more shells (non painted ones) and put them in with your guy in isolation
but rise/dip them in the water first
then he can look for another shell and will probably be fine once you put him back in
also you should have at 6 inches or three times the size of your biggest crabs worth of sub (which we is bigger) in your tank

I suggest cleaning the shells you already have, if you haven't tried that yet. Give them a quick boil and when cool dunk them in some saltwater. This can trick them into thinking they have totally new choices. Might get one or both to change!