We are pretty new to a fish tank and still learning but the fish have been thriving so we let the kiddos pick out some new fish and they picked two crayfish. The lady at the store said they would be fine together but to give them two separate "shelters" in the tank because they can be aggressive. We have had them for about two months now and they have been fine but over the weekend I found one of the crayfish dead with it's head missing and no sign of the head anywhere in the tank!!! On top of it, one of the crayfish was white, one was blue. I was thinking the white one may have eaten part of the blue one since part of his body is nowhere to be found and now the white crayfish is turning blue, is this totally bizarre or what?! I told my husband I don't think we should get another crayfish but the kiddos are devastated and want to get another one of course.