The culprit is known as a meadow vole, but is often confused with gophers or field mice. Voles not only leave unsightly burrows in a yard, but can also gnaw at the base of a young tree or shrub causing irreparable damage.
Mainly, voles will eat the stems and blades of grass causing dieback in lawns. At times they may even cause damage in a garden by eating bulbs and seed potatoes.
Vole control can be a problem. As many people are aware, two young girls died in northern Utah when a pesticide applicator used aluminum magnesium phosphine fumigant near a family home in an effort to control voles.
For average yard owners, vole control begins with identifying the opening in the burrows. Place a mousetrap baited with peanut butter perpendicular to the opening of the burrow. The wider the burrow, the more traffic that is occurring inside.
Other control means involve poison baits such as Rodex or d-Con. Purchase them at most hardware or garden stores.
Poison baits can be potentially hazardous to other wildlife, children, or pets. Be sure to place the baits where they are not accessible to those other than the targeted species.
For more info, visit: http://extension.usu.edu/files/publications/publication/NR_WD_009.pdf