Was watching the tank tonight and saw my Gold Head Sleeper Goby opening his mouth wide at one of the cleaner shrimp. I thought he was just saying "Back off, I am bad" to the shrimp but then right before my eyes he moved forward and let the cleaner shrimp clean the inside of his mouth! What a Cool sight! Got the camera and ran back but they were already finished and the Goby went back to the other side of the tank. Can't wait to catch that pic!