There are about six different species of voles that live in North America. The most prevalent in landscaped gardens is the pine vole. The pine vole is about three inches long, weighs one ounce, and has chestnut hair, a short 1/2 inch long tail and tiny ears. You are more likely to see signs of voles than the voles themselves. Pine voles spend most of their lives under the ground in burrow systems feeding on plant roots.
Look for their presence by locating their circular burrow entrances not more than 1" - 1.5" in size and by lifting mulch to reveal long narrow trenches or runways that are serpentine, and that wind around obstructions. Voles can burrow into the root systems of landscaping shrubs and trees, causing young specimens to experience dieback or to begin to lean. These rodent pests will also gnaw on a tree trunk and at the base of a shrub. In addition, voles damage flower bulbs and potatoes in the garden. Mainly, however, voles eat the stems and blades of grass. And the runways they leave behind in the process make for an unsightly lawn.
Unlike many other small mammals, voles do not hibernate. Instead, they are active throughout the year. And depending upon where you live, voles can have four or five litters each year with an average of three babies per litter. Female pine voles have a gestation period of about 24 days. Due to this prolific ability to reproduce, vole populations grow quickly.