lol, I have wondered that too but there's no clock in my room! I usually leave a lamp on in my room cuz I get back home after the lights go out and don't want to freak them out by turning the room light on when its dark. (Done that a couple times - not good!) And when I get home, everybody's in sleep mode. My clowns are in their little cave, my cardinal is usually darting around and really active and I have no clue where my angel hides. My shrimp is usually out too. But its like they know its bed time. They used to do that before I got the aquarium lights, too. Funny little guys, aren't they?