Seeing small, scattered holes suddenly appear across a lawn or garden bed is a common sign of squirrel activity. These energetic rodents are driven by powerful, instinctual behaviors related to survival and food acquisition. By understanding the specific motivations behind this behavior, it becomes easier to manage their presence and protect vulnerable areas of your yard.
Primary Motivation: Food Caching for Winter
The most frequent reason for a squirrel to dig is a behavior called scatter hoarding. This strategy involves burying individual food items, such as nuts, acorns, and seeds, in hundreds of shallow caches spread across a wide territory. This dispersal method prevents the loss of the entire food supply if one cache is discovered by a competitor. Squirrels are highly active during the fall, preparing for colder months when foraging becomes difficult. They rely on spatial memory and a keen sense of smell to locate these buried treasures later, sometimes even through snow.
The typical hole left by this caching is small and shallow, usually only one to two inches wide and quickly covered with soil or debris. Research shows that eastern gray squirrels do not recover between 20% and 60% of their buried items, effectively planting the next generation of trees.
Digging for Dinner: Hunting Grubs and Forgotten Seeds
Squirrels also dig to find food that is already present, not just for storage. This foraging includes retrieving their own previously cached items, resulting in the same small, shallow holes as the initial burial.
A different type of foraging involves hunting for non-plant food sources just beneath the soil surface. Squirrels are omnivores and will dig for insect larvae, particularly white grubs, which live in the topsoil and feed on grass roots. This grub-hunting activity often leads to slightly more irregular or patchy disturbances compared to the neat, single-item caching holes. If the squirrel is not immediately successful, they may move on quickly, leaving behind a series of small, exploratory divots.
Identifying the Culprit: Tree Squirrels Versus Ground Squirrels
The type of digging observed can help determine the species responsible, as tree squirrels and ground squirrels exhibit different behaviors. Tree squirrels, such as the common gray or fox squirrel, are the primary culprits behind the scattered, shallow holes used for food caching and retrieval. Their digging is short-term and focused entirely on food, not habitation.
Ground squirrels, including species like the California ground squirrel, engage in digging for a completely different purpose. These burrowing rodents create extensive, permanent tunnel systems for shelter, food storage, and raising young. Their holes are typically larger, often found near foundations or beneath bushes, and lead to deep burrows. If startled, a ground squirrel runs into a large hole in the ground, while a tree squirrel scurries up the nearest vertical structure.
Discouraging Squirrel Digging in Specific Areas
Managing squirrel digging in targeted areas involves making the location less attractive for both caching and foraging.
Food Removal
One effective strategy is removing easy food sources, such as fallen nuts, seeds, and fruits, which eliminates the incentive for the animal to bury items there. Securing or removing bird feeders, which are a major source of cached seeds, can also significantly reduce activity.
Physical Barriers and Deterrents
Physical barriers can prevent access to vulnerable spots like garden beds or newly planted bulbs. Laying chicken wire or mesh netting just below the soil surface or over the top of a garden bed creates a deterrent that blocks digging while still allowing plants to grow. Natural deterrents that utilize the squirrel’s sensitive sense of smell, such as sprinkling cayenne pepper or chili powder, can also be applied to the soil surface. These spicy compounds create a temporary, non-harmful repellent that discourages them from digging in the treated area.