Voles are small rodents often confused with mice, and they do engage in digging, though their activity is often misinterpreted. Their primary subterranean activity involves creating shallow runways and surface openings rather than deep, permanent tunnels. They are compact, stocky animals with short tails and small eyes. Their digging is directly related to their diet and need for protective travel routes. Understanding the specific structure of their excavations is the way to correctly identify their presence in a yard or garden.
The Vole Tunneling System
Voles utilize a dual system for their movement, consisting of shallow underground tunnels and distinctive surface runways. The surface runways are the most recognizable sign of their presence, appearing as narrow, well-worn pathways about one to two inches wide through grass or mulch. These paths are created as the voles clip the grass close to the ground, allowing them to travel while staying concealed by the surrounding, taller vegetation.
These runways connect to numerous small, circular entry and exit points for their burrows. These openings are typically about the size of a golf ball, ranging from one to one and a half inches in diameter, and often lack the significant dirt mounds seen with other pests. The shallow tunnels just beneath the surface, especially those of species like the meadow vole, can make the ground feel soft or spongy when walked upon, indicating the presence of a hollow network below.
Distinguishing Vole Tunnels from Mole Tunnels
Differentiating vole activity from that of other lawn pests is done by observing the presence or absence of soil mounds. Moles, which are insectivores, create large, volcano-shaped hills of loose dirt, known as molehills, as they dig their deeper tunnels. They also leave behind raised, visible ridges on the lawn surface where their shallow feeding tunnels are located.
In contrast, voles generally do not create these prominent dirt mounds, leaving only small, clean, open holes at the surface of their burrow entrances. Vole activity is characterized by the flat, crisscrossing surface runways, which are paths of trampled and clipped grass, not raised ridges of soil. Mole tunnels are constructed for hunting insects, while vole runways are sheltered travel routes connecting feeding areas and burrows.
Mole tunnels are often deep and permanent, while voles typically operate just below the surface or within the thatch layer. The damage left by moles is primarily the disruption of the soil and grass roots from their tunneling, whereas vole damage is concentrated on the vegetation itself.
Why Voles Dig Near Plants
Voles dig and tunnel with the specific motivation of accessing their primary food sources, as they are herbivores with a preference for vegetation. Their diet includes roots, bulbs, seeds, and the bark of trees and shrubs, especially during the winter months. The tunnels they construct are, in effect, supply lines leading directly to these subterranean food items. Voles often follow the path of a root system or seek out a buried bulb, which explains why they are frequently found near garden beds and trees. This behavior contrasts sharply with moles, whose digging is driven by the hunt for earthworms and grubs, not the consumption of plant material.