That's interesting! I thought they were subterranean like moles but maybe they just take cover underground as this from Wikipedia states:
~ Nests are used as nurseries, resting areas, and as protection against weather. They are constructed of woven grass; they are usually subterranean or are constructed under boards, rocks, logs, brush piles, hay bales, fenceposts, or in grassy tussocks. Meadow voles dig shallow burrows and in burrows, nests are constructed in enlarged chambers. In winter, nests are often constructed on the ground surface under a covering of snow, usually against some natural formation such as a rock or log. ~
Cute little critters but it's such a shame they have to eat plants that we love.
