HCA: Hermit Crab Association

My largest crab came back up from a molt this morning. So, naturally, I wanted to watch him for awhile. He decided to change shells, but right as he found a shell he liked, my smallest crab came up and picked a fight over a shell that's way too big for him. I seperated and isolated the smaller one. I put him back in about an hour later and he still went after the other crab. Is this because the other crab was down for so long that the other forgot about him? Did the smaller crab just decide the tank was his because he couldn't find the other one?

It could be either of those things, or the one that just came up from molting may smell different from molting. Baths are normally not recommended, but if it continues you might try dipping both of them in a dish or tank temperature dechlorinated water to make them both smell neutral.

I heard that when you buy new crabs you are meant to clean or rearrange the tank so that the other hermit crabs don't fight with the new ones because of territorial issues. I don't know if it's true or not. I had 2 hermits and when I brought another 2 and put them together, Darth Vader and Pinchy were kind of picking on each other. Nothing major though. Is it only a certain gender that likes to protect it's territory? Like how only male cats fight off other male cats if they are in their territory.