Hi all, our pistol shrimp has been acting "odd" lately. It no longer hangs out in its burrow with his paired yellow watchman goby, he cruises the bottom of the tank day or night. He used to be a very active digger and now just looks lost wandering around the tank bumping into the sides. Sometimes he carries around a small rock or shell which is entertaing. Is this normal. All parameters in this FOWLR tank check out good. Thanks in advance.