Last weekend I was woken up at approximately 5:30AM by one of my cats, who was clawing frantically at the door. They both used to do this when we first adopted them, but after a while they realized that night time is sleep time for the humans and they can have plenty of fun without us; thus, any attempts to get into the bedroom at night are very rare and very half-assed pawing.
I let the cats in and got back into bed, expecting Sophie to demand petting (she's one who if you have a hand and it isn't moving, she'll pet herself with it. She also doesn't know how to lay or sit still unless she's totally passed out.) Instead, she flopped across my fiance (who was still asleep) and watched her brother, who sat directly beside me and stared straight at the corner for a good ten minutes. He was tracking something -- up, down, a little left, a little right, etc. -- but all within one corner. I couldn't see anything for him to be following, but he was rather intent. After a bit he hopped to the floor and sat between the corner and my side of the bed, at an angle which allowed him to see both at the same time. Sophie was still in the same spot, watching him. It was bizarre. Normally if something is around I can tell, but I felt and saw absolutely nothing.
What do you think it was, TQC?
Edit: Man, you guys are no fun tonight :P