Folks, if you've recently upgraded or renewed your annual club membership but it's still not active, please reach out to the BOD or a moderator. The PayPal system has a slight bug which it doesn't allow it to activate the account on it's own.
I guess it depends on the type of crabs, mine don't seem bother each other. It's kind of cool/creepy how they come out of the substrate when I feed the tank.