According to Oregon State University wildlife biologist Dan Edge, if you live in western Oregon, you most likely have either the gray-tailed or Townsend's vole. Both of these western Oregon species like grassy or meadow-like habitats. In eastern Oregon, the Montane vole is the most likely lawn pest. These species of voles build runways through and under low-growing vegetation, especially in rural areas. They are difficult to spot, as they seem to always be on the run.
Voles are active both day and night.
They are vegetarians, eating a wide array of green plants such as grass, clover, buttercups, false dandelion, and horsetail. Since some of these are lawn weeds, the voles may be helping to eradicate unwanted weeds. But if voles are turning your lawn into a rodent freeway interchange, you may want to do something about them. Vegetation management is the key to keeping vole populations in control. If you keep your lawn short and dethatch it yearly, voles will find less habitat on your property.