Or sparrow. I close my run every night, but birds creep in from a small opening in the top, to peck at the feed.They leave pretty big tracks even though they have such tiny toes
I have hardware cloth over the top below the roof. When I lived in town I had a rat and its pretty gross. So here I buried the hardware cloth about 8-10 inches and then bent it so it went out away from the run 8-10 inches. I will need to redo this this summer. I thought I had proofed this run. Whatever it is it has a hole. I put a couple of traps out and covered them with milk crates so the chickens cant get in them. Nothing last night. I don't know where a rat would come from. We live in the country away from farms with livestock. I do have chipmunks and field mice.