How do I get rid of voles ? They are digging multiple holes in our yard, Don Schuessler Coburg, OR
Lane County Oregon
http://extension.oregonstate.edu/gardening/2015/04/moles-voles-and-gophers-dig-garden Though voles live in little tunnels, they spend time above ground eating grass and nibbling on other plants.The mouse-size voles leave a lot of small holes and connecting runways If there are visible "volcanoes" of soil you may have gophers or moles.
Trapping is an option if you have a small area. On larger areas trapping may not be efficient. Often multiple voles are found in one tunnel area as they live in family units. As voles are short-tailed meadow mice they can be trapped with snap type mouse traps. You can bait the traps with peanut butter, celery or other vegetables.
The first practice to control voles is to mow grass and weeds short. They use the taller grass and weeds as cover that allows them to forage more safely. Short vegetation allows their natural predators to control them better.
This website has a very good discussion of voles and their control.