The presence of squirrels in a yard is common across North America, involving a mix of natural behavior and potential conflict with human interests. Common species like the Eastern gray, Fox, and Red squirrels are adaptable rodents that thrive in suburban and urban environments. Determining whether their presence is negative requires balancing their role in the local ecosystem against the risks they pose to property and health.
The Ecological Role of Squirrels
Squirrels serve a distinct function in local ecosystems, acting as inadvertent agents of forest renewal. Their habit of scatter-hoarding, burying nuts and seeds for later consumption, results in many forgotten caches. These unrecovered stores are effectively planted, leading to the germination and growth of new trees and supporting woodland regeneration.
Their role as a food source also helps maintain the balance of the local food web. Squirrels are a common prey item for various urban and suburban predators, including birds of prey and terrestrial hunters. This predation helps regulate the overall population of small mammals. Foraging activities also contribute to soil aeration and the dispersal of fungal spores, which are beneficial for forest health.
Structural and Landscape Damage Risks
The continuous growth of a squirrel’s incisor teeth necessitates constant gnawing, a behavior that poses a significant threat to structural integrity. When squirrels access attics, walls, or crawl spaces, they chew on materials like wood beams, siding, and insulation to maintain their teeth or create entry points. This destructive chewing extends to electrical wiring, which they target for gnawing and nesting material, creating a serious fire hazard from exposed copper or short circuits.
Inside a structure, squirrels shred fiberglass insulation to build nests, greatly reducing its thermal efficiency and contaminating the space with urine and feces. This contamination can lead to unpleasant odors and require costly professional cleanup and material replacement. On the landscape, they cause damage by digging up freshly planted flower bulbs, which they consume for their nutritional content. Squirrels also strip tree bark, particularly from young trees, which can girdle the tree and compromise its health.
Potential Health and Safety Concerns
While squirrels are not primary carriers of rabies, health concerns arise from the parasites they host. Squirrels frequently carry fleas, ticks, and mites, which can easily transfer to domestic pets and humans, especially if they nest near or inside the home. These parasites are vectors for serious diseases, including Lyme disease, Rocky Mountain spotted fever, and typhus.
Direct exposure to squirrel waste also presents a health risk. Their droppings and urine can transmit bacterial infections such as salmonellosis and leptospirosis through contact with contaminated surfaces or soil. A squirrel that is cornered or appears sick may bite or scratch, which carries a risk of bacterial infection or, in extremely rare cases, rabies transmission.
Humane Deterrence and Management Strategies
Effective management focuses on exclusion and deterrence rather than removal, starting with securing food attractants. Bird feeders should be fitted with baffles or switched to less appealing seed types, such as safflower. All outdoor pet food should be removed, and garbage cans must have tightly secured lids to prevent access.
To prevent structural entry, inspect the exterior of the home for openings the size of a golf ball or larger. Seal these openings with durable materials like galvanized hardware cloth or sheet metal. Overhanging tree branches that provide access to the roof or gutters should be trimmed back at least six to eight feet from the structure.
In the garden, physical barriers are highly effective. Cover newly planted bulbs with a layer of chicken wire or hardware cloth, anchored to the ground until the soil freezes. Applying capsaicin-based repellents to inedible plants or using motion-activated sprinklers can also discourage foraging activity.