The presence of holes in a yard often signals an active wildlife visitor, and identifying the animal responsible depends entirely on the purpose of the digging. Animals primarily dig for one of two reasons: to establish a safe, long-term shelter, or to forage for an immediate food source like insects or roots. Holes dug for shelter tend to be large, permanent entries to an underground network. Holes dug for food are typically shallower, smaller, and scattered across a lawn. Accurately assessing the size, shape, and location of the damage is the first step toward determining which species is involved and implementing an effective control strategy.
Burrowers and Den Builders: Large Entry Holes
Animals that establish permanent underground residences create large, distinct entry points that lead to extensive burrow systems. Groundhogs, also known as woodchucks, are known for their large tunnels, often creating entrances between 8 and 12 inches in diameter. These burrows can be complex, extending up to 30 feet in length and reaching depths of 5 feet or more. A telltale sign is the fan-shaped mound of fresh dirt and rocks deposited directly outside the main entrance hole. Groundhogs typically choose locations that offer cover, frequently digging under sheds, decks, fences, or dense shrubbery.
Other den builders include canids like coyotes and foxes, which use burrows primarily for raising their young. Coyote den entrances are usually taller than they are wide, often measuring around 12 to 24 inches high and about one foot wide. These animals often utilize existing burrows, widening them to suit their needs, and positioning them on slopes or hillsides for better drainage. The den system itself can be quite long, sometimes exceeding 15 feet in length with multiple exits for quick escape.
Foragers and Hunters: Shallow or Scattered Digging
A different type of damage results from animals searching for food, characterized by numerous, shallower disturbances across a lawn or garden area. Skunks are common culprits, creating small, conical holes approximately 1.5 to 4 inches in diameter. These precise holes are often the size of the animal’s nose, resulting from the skunk pressing its snout into the soil to hunt for beetle larvae (grubs) and earthworms. When a skunk finds a concentrated food source, these small holes can become highly numerous, making the affected area look like it has been tilled.
Raccoons also forage for grubs, but their method of digging is significantly more destructive and less precise than that of a skunk. Raccoons use their dexterity to peel back or tear up large, messy patches of sod or freshly laid turf. This action exposes the grubs or worms concentrated just beneath the surface. This type of widespread surface damage, where turf is lifted rather than simply punctured, is a strong indicator of raccoon activity.
The damage caused by armadillos is similar to foraging, characterized by shallow, irregular rooting marks and small holes created when probing for insects and worms. Domestic dogs may also create holes, which are typically large, irregular, and often located near fences or property boundaries due to anxiety, boredom, or an attempt to escape. Understanding that these animals are motivated by an immediate food reward, rather than a need for permanent shelter, is essential for selecting appropriate solutions.
Effective Strategies for Exclusion and Deterrence
Exclusion methods must directly address the animal’s motivation, whether it is seeking shelter or a meal. For animals that dig large, permanent burrows for shelter, like groundhogs and coyotes, physical exclusion is the most reliable strategy. This involves installing wire mesh fencing, specifically an L-footer barrier, around vulnerable structures such as decks, sheds, and porches.
An L-footer involves burying the bottom of the wire mesh at least one foot deep. The mesh is then bent outward at a 90-degree angle for another foot. This horizontal barrier prevents the animal from digging directly down and under the fence line. If an animal is already residing in a den beneath a structure, a one-way door mechanism can be temporarily installed to allow the resident to exit without being able to re-enter.
For foraging animals like skunks and raccoons, the focus shifts to habitat modification, specifically removing the food source that attracts them. Treating the lawn for grubs using either chemical insecticides or biological controls, such as beneficial nematodes, removes the primary incentive for digging. Additional deterrents include removing other readily available attractants, such as fallen fruit, unsecured garbage, and pet food left outdoors. Motion-activated devices, like lights or sprinklers, can also be employed to startle nocturnal foragers and encourage them to seek food elsewhere.