Reminds me of what happened in my house a few days ago. Over the past few months, I've learned that there is a mouse in my house too. It lives in the chimney pipe, and occacionally makes quite loud scratchy excursions across the gypsum plates which have been fixed to the ceiling. Usually, the sounds it makes are very faint, and only bother me when I want to go to sleep. A few days ago, I heard a mild scratching noise again when I was about to drop off, but forgot about it. Until I woke at 5 AM by a very loud scratching noise coming from the door which opens onto the central stairway. It was very loud---too loud to go to sleep by again. In fact, the door was being rattled as well. 'Some mouse!', I thought in my sleep-drugged brain. I turned over noisily in the hope that the sounds I made would scare the animal off. It did, for about ten seconds, then it started again. I got quite POed, threw off the covers and turned on the light in the hope of seeing the critter scuttle away. I was midly surprised to see there wasn't any sign of an animal hastily retreating and that in fact the source of the sounds seemed to be coming from outside. I opened the door and got a major scare when a very large white cat scooted between my legs. Now neither I nor my upstairs neighbour have a cat, so I was very surprised to see one in my house, much more so at 5 AM in the morning!
In any case, after waking the neighbour we quickly figured out it had snuck across her balcony from the house next door, got into her appartment via the open balcony door, and quietly tripped out when she went to the toilet in the middle of the night. Unfortunately for the cat, she closed the door on it so it was stuck in the hallway with no way of getting back to its own house. It knew it had to get back through the door, hence all the scratching.
It sure was the biggest mouse I ever saw ;-).
