I have been finding droppings around the first floor since the cats moved out. (They all live with Jessie in my parents' house. Only Remy the Pomeranian is left with us). Today I found holes chewed in both the screen doors leading out to the back deck. I patched them with duct tape, but also resolved to start closing those doors at night to inhibit further incursions.
Tonight the mouse saga came to an end, I hope. Dave was already abed and I had just finished cleaning the kitchen, when I heard a scritch, scritch from from the corner of the dining room. I looked down by the wastebasket, and, sure enough, the most adorable dove-grey mouse was sitting there. I resolved to catch him and Put Him Outside. I failed. However--with Remy's help and herding--I managed to get him to run out the open screen door onto the deck by himself. Yay us! I closed both deck glass doors (we'll get airflow from somewhere else from now on) and started turning off the lights before taking myself to bed.
Then I saw a flash of movement under the tv cabinet in the living room. Another mouse! I got him to run behind the open front door, and then I pushed open the screen door and shivvied him out into the night. Fingers crossed that that's the last of the interlopers. They really are adorable with their tiny faces, huge liquid black eyes, long twitchy whiskers, and big soft ears--even Dave says so. But I much prefer them to live outside.