It was late last night. Well, early this morning, technically. I was sitting in bed playing Pocket Planes on my iPhone.
A bat flew in through the bedroom door, did a circuit of the bedroom, then left again.
I spent quite a while roaming the flat with a torch, looking for it, but never found any sign of it. I went back to bed and sat up reading and playing with planes again, waiting for it to return. It never did.
It must have got in through a relatively small window left open in the kitchen, flown through the living room, into the hall, then into the bedroom. Either it found its way back out again, or it’s gone into hiding somewhere in the flat. They’re tiny creatures when folded up, so it could go undetected pretty easily. They eat a lot of insects each night, though, so if was still in here, I’d have expected it would fly again to look for food.