The bottoms of both of these pictures are right at the edge of the pond, so all the prints you're seeing are actually out on the frozen pond. One of the sets of trails actually start at a hole at the base of a pile of snow-and-ice covered weeds that are bent over on the slope down to the pond...my guess is mouse or vole?
You can definitely see where some are from a much smaller animal, where their hole body made a path in the snow, where the bigger animals just left footprints.
The dogs always get a kick out of following critter prints in the snow - I just have to make sure they're not tempted to go across the pond (even though it's frozen, I'd rather play it safe). So far the dogs seem to be aware and aren't too tempted to walk across the frozen pond...
Just think, it won't be too much longer and the pond will be all thawed out and everything will be green again!