I thought something was wrong with my eyes, because I kept having the impression of a flicker of movement when there was nothing there: like, near the bottom of a curtain; under a table.
Then finally I saw it. A mouse. He must have gotten in when the front door was open. The broken screen door doesn't close fully and leaves a couple of inches.
My god, mice move fast. I've been noticing that flicker for a couple of days, I think. But never saw him.
He gets to stay until tomorrow, since I am too tired to do anything but confine him to the front room tonight. If it's warmer tomorrow maybe I can just chase him out the front door again.