The discovery of holes and disturbed soil in a yard can be frustrating for any homeowner. The damage, often appearing overnight, signals that a local animal has been actively foraging or excavating. To effectively address the issue, you must first become a detective and analyze the specific evidence left behind by the culprit. By carefully examining the size, shape, and location of the digging, you can accurately identify the animal responsible and understand the behavior driving its activity.
Shallow Holes and Disturbed Turf The Foragers
Animals that create shallow disturbances are typically foraging for insects, grubs, or worms just beneath the grass line. The most common sign of this activity is turf that has been torn up or perforated in a messy, erratic pattern. Raccoons cause widespread damage by using their front paws to lift and peel back sections of sod, often rolling the grass back like a carpet to access food sources like white grubs. This disturbance results in large, irregular patches of loose turf.
Skunks, by contrast, leave a more precise signature, characterized by numerous small, conical holes. These foraging probes are typically no more than three inches deep and one to three inches wide, appearing as if the lawn was poked repeatedly with a screwdriver. They use their long front claws and pointed noses to dig directly into the soil to extract beetle larvae and earthworms. Finding five or more grubs per square foot can be enough to attract both skunks and raccoons, driving this shallow digging behavior.
Other small foragers, such as squirrels, leave miniature holes specifically for burying or retrieving cached nuts and seeds. These holes are generally very shallow and scattered. This activity is distinct from the aggressive, widespread damage caused by grub-hunting animals, making the pattern of damage the best indicator.
Mounds and Runs The Subterranean Tunnelers
When damage involves mounds of soil or raised pathways, the culprit is an animal that lives underground, creating extensive tunnel systems. Distinguishing between these subterranean pests requires close attention to the architecture of their earthworks. Moles, which are insectivores, create two distinct signs: volcano-shaped mounds and raised surface runways.
The mole mound is symmetrical and conical, formed when the animal pushes finely sifted soil straight up through a vertical tunnel. The entrance hole is usually sealed or hidden at the center of the mound. More common is the surface run, which appears as a raised, soft ridge connecting the mounds, created as the mole tunnels just beneath the grass line in search of earthworms. These tunnels are essentially food traps, as moles do not eat plant roots.
Pocket gophers, which are herbivores, create a different type of mound characterized by a crescent or fan shape. The entrance hole to a gopher’s deeper tunnel system is typically plugged with soil and is offset to one side of the fan-shaped mound, unlike the central opening of a mole mound. Gopher tunnels are generally found deeper than mole surface runs, often four to eighteen inches below ground, where the gopher feeds on plant roots and tubers.
Voles, which are small rodents, typically do not create large mounds but leave behind specific signs. The most definitive evidence of voles is a network of visible, cleared surface runways, about two inches wide, that crisscross the lawn or garden under protective cover. These runways connect their numerous small, neat, round burrow entrances, which measure only one to two inches in diameter and are often concealed near plant bases or under mulch.
Large Entrance Holes Den Builders and Cache Diggers
Holes with a large, open diameter generally indicate an animal is constructing a permanent den for shelter, nesting, or hibernation. Groundhogs, also known as woodchucks, are the most prominent builders of this type of burrow. Their main entrance hole is substantial, often measuring ten to fourteen inches across, and is immediately accompanied by a large mound of excavated soil and rocks.
This main entrance leads to a complex, multi-chambered tunnel system that can extend up to sixty-five feet horizontally. Groundhogs also create several auxiliary exit holes that are often inconspicuous and lack the large mound of dirt at the opening. These dens are usually located near foundations, under sheds, or in dense vegetation, providing easy access to cover.
Rabbits may also dig, though their excavations are generally smaller and less complex than those of groundhogs. Some rabbit species create shallow scrapes or small burrows used specifically for nesting and raising young, which may have a small dirt mound nearby.
Finally, a domestic dog is a common source of large, erratic holes, often driven by instinct to hunt underground prey, bury a treasured object, or dig a cool spot to lie in during warm weather. Dog digging lacks the consistent, structured pattern of wildlife burrows, often resulting in deep, asymmetrical pits near fences or in random, favored locations.