My snakes head is completely under water?

today is the first time hes done this and ive had him for a year anda half. im pretty sure he's not drinking out if his water bowl because when he is, he uisually just stiks the tip of his head in. today i caught him just siting in the water w/ his whole head underneath, and hes done this 2ce now. both times ive only gently pulled him out of it and set him aside his bowl. right now hes just moving around like he usually dus. hes a ball python if its any help. thx :)