Of course I had to photograph the carnage. Fortunately, there was no blood.
The mouse had not gnawed into anything that I could see, but his/her "leavings" were obvious. It had burrowed into the sandy floor and was digging tunnels under the dog's kibble bin. It would only be a matter of time until it started nibbling on potatoes or ripping into plastic bags of rice and pasta.
I baited three traps with peanut butter and waited. A few days later, we found that one of the "snap" traps had worked. Poor thing. I've kept the traps down there in case there are other mice, but it's been more than a couple of weeks and there is no sign of another.