We often see footprints in the snow around our house. I always wonder who put them there. They are too small for human.
We do see quite a few animals in the yard. Squirrels and chipmunks are very common. We have seen deer and even opossum. And during the summer we sometimes hear the distintive bark of a red fox, although we have never seen him.
But the most likely culprit is a neighborhood cat.