I live in the Willamette Valley region of Oregon, USA. A few days ago I noticed these rodents digging in my compost pile. This was in the early-afternoon. If I got too close (closer than 4 ft) they would retreat to a pile a branches and trimmings.
The compost pile is well composted and over a year old. I'm not sure what they were eating, but there wasn't any un-composted kitchen food (unless some seeds remained). Squirrels may have hidden something in the pile. There are plenty of worms in the pile.
They have a white underside, the eyes aren't overly large. The coat is brownish-gray. I couldn't see any color variation on the tail. My pictures are low resolution, but I didn't notice large hairs on the tail. I'm guessing the body is about 3" - 4" long.