my RTB does that. the first time scare the bagesus out of me. My boyfriend had opened his tub to get him and went, "uhm. amy...hes not here" well i freaked out, looked formyself, and found that he wasn't! I looked under his hides, and moved a little bit of bedding on one side of the tub, and all of a sudden his little head popped up out of the other side of the tub. The look was priceless though (uhm. excuse me. im right here. but dont touch me. im sleeping. no go away.)