Noah had a rough night. He had to wake up in the morning because his sheets and comforter had fallen off (which, while annoying, is not a new experience for him).

I was in the shower and he came in to tell me what a bad night he had because he had to wake up in the middle of the night to put his covers back on because he was freezing.

He ended the conversation with, "My sheets are alive."

I suppose that it is the only logical explanation for sheets mysteriously inching their way off one's body in the middle of the night.