I get asked that a lot. Most people have never heard of such a thing. Certainly, have never seen one. But Voles are very numerous. Being a prey species these "field mice" reproduce accordingly. They are top menu items for most furbearers such as fox, coyotes, bobcats, badgers, etc. Also, the feathered predators like owls, hawks and small falcons i.e., American Kestrel. Voles are widespread throughout most of the United States. They do not hibernate. Rather they spend the winter months in a burrow that they dig to get below the frost line. They will readily use Mole burrows to travel and to help start their own burrows. Also, by traveling these burrows they can keep themselves concealed from all of these predators.
They are basically a mouse species. Therefore, their major food source is weed seeds, flowers seeds, root tubers, etc. Therefore, in our newer sub-divisions in the Kansas City metro area that are being developed into residential communities their population can really explode. With this development the newer homes are surrounded by overgrown fields. With all these weeds and wildflowers there is plenty of seeds to go around. Spilled bird seed if you feed the birds. They love it. And if times get tough, like a lot of snow or ice in the winter. They will start girdling the bark off small trees and bushes. And because of the new development there are less predators to control them naturally.
And so here is where they become a problem for most people. Particularly around the newer subdivision mentioned above. Any property that has a lot of overgrown fields are vulnerable to a high population of Voles. They have the preference of burrowing up along your sidewalks leading up to the front door, your driveway, your back patio, any sold object that they can burrow under. This solid form of concrete allows for some security from burrowing predators. Your landscape provides a lot of food for them and then again, the surrounding properties. Then between these burrow entrances they have the habit of clipping the grass off right at the ground level to create a sort of "highway" that they can zip thru fast. Further in the spring and summer the grass will grow tall and form a sort of tunnel to help conceal their movement.
OK, you went outside and found some burrows up along the front sidewalk. What to do? You can use traps. But I have found that to be really labor intensive and they really don't bait well. They can be finicky. The other option is rodenticide. You can purchase this at most hardware stores. Be sure to read the instructions. The bait is best placed into the burrows so that it will fall below ground level. This will ensure that now other wildlife like birds will not eat it. When baiting its best to be really persistent as well. Best of luck!