Down the lottie, on the weekend when I made a big wire container to make some leaf mold, i raked up a bit of dried grass etc that was lying over a piece of wood that was separating two beds. The children noticed that this wood (which has holes in the middle) looked hollow underneath. So I lifted it up a little and it looked as if something has dug little tunnels underneath it, a few centimetres deep and away under some more wood.
I figured there might be something hibernating under there...what? A field mouse? a vole? I saw one or two tiny mice over the year, maybe it is the same one?
In any case I put back the dried grass etc that had been covering it in case that was its "winter quilt" and even put a bit more leaf etc around the area to insulate it. It is amazing what life grows in a veg garden. isn't it?