I'd say my snakes sleep for fun. Well, Hades has his fun every night trying to escape out of his tank. He does it all the time and after 3 succes a few years ago...hasn't succeeded since. Yet he still tries. I think Kozma has his fun by trying to conjure the biggest turd possible, than dragging his butt along the side of his tub to smear his poopies everywhere (yes he does that).