There is a tendency among homeowners to treat squirrel activity in the attic as a nuisance rather than a genuine problem. The scratching sounds overhead are easy to dismiss, especially when the animal responsible looks harmless from the backyard. But across Hamilton, Burlington, and Oakville, Action Pest routinely uncovers attic damage caused by squirrels that is far more extensive than the homeowner anticipated, and the longer the animals are left undisturbed, the more costly the resolution becomes. Squirrels in an attic are not houseguests. They are a structural, electrical, and biological problem that warrants prompt professional attention.
How Squirrels Get Into Your Attic in the First Place
The eastern grey squirrel (Sciurus carolinensis) is the species most commonly encountered in attic intrusion calls across urban and suburban Ontario. Agile, persistent, and highly motivated to find enclosed denning spaces, particularly during the spring birthing season between February and April and again in late summer, squirrels exploit a surprisingly narrow range of vulnerabilities to gain access to a structure.
Roof vents are among the most frequent entry points. Standard plastic or aluminium vent covers offer minimal resistance to a squirrel that has identified the space behind them as suitable nesting territory. Deteriorated or missing soffit panels, gaps at the junction between roofline fascia and the exterior wall, and damaged drip edge flashing all represent openings that squirrels will widen over time using their continuously growing incisors. Overhanging tree branches that provide direct rooftop access are the most common enabler of initial contact, and trimming them back is consistently among the first prevention recommendations made by wildlife professionals across the region.
The Damage Squirrels Cause Is Rarely Superficial
Once inside an attic, squirrels behave in ways that cause damage across multiple systems within the structure. Insulation is the first casualty. Squirrels tear apart batt and blown insulation to construct nesting material, compressing and displacing the insulation in ways that significantly reduce the thermal performance of the building envelope. Homeowners who have had an undiscovered squirrel presence for an extended period frequently face insulation replacement costs that dwarf the original wildlife removal expense.
Electrical wiring represents the most serious hazard associated with squirrel activity in attics. Squirrels gnaw on wiring continuously, not out of nutritional need but as a behavioural necessity driven by the constant growth of their incisor teeth. Stripped or severed wiring in an attic space creates a documented fire risk. The Electrical Safety Authority of Ontario advises homeowners to have attic wiring inspected following any confirmed wildlife intrusion, and this recommendation should be taken seriously regardless of how brief the suspected occupancy period was.
Roof decking, vapour barriers, HVAC ducting, and stored belongings are all subject to damage in an attic where squirrels have been active. Additionally, squirrel urine and droppings accumulate in nesting areas, creating odour, staining, and a potential biological hazard that requires professional remediation before the space is considered safe for routine use.
Seasonal Timing Makes Early Action Critical
Squirrel intrusions follow predictable seasonal patterns that homeowners across Burlington and Oakville should be aware of. The two peak periods for attic entry correspond directly with the species’ two annual birthing cycles. Female squirrels actively seek enclosed, thermally stable nesting sites in late winter through early spring, and again in late summer through early autumn.
A squirrel that enters an attic and successfully raises a litter inside the structure presents a compounded problem. The young, once weaned, may establish their own home ranges that include the same property and the same entry points. Without professional exclusion work that addresses the structural vulnerabilities, a single intrusion event can develop into a recurring annual problem that affects the same property season after season.
Under Ontario’s Fish and Wildlife Conservation Act (S.O. 1997, c. 41), squirrels are classified as wildlife and their capture and relocation is subject to provincial regulation. Removing a nursing mother without accounting for dependent young is both an animal welfare concern and a practical problem, as kits left behind in a wall or ceiling cavity will not survive and can create secondary odour and pest issues as decomposition occurs. Licensed wildlife professionals are equipped to manage the full scope of these situations in a manner that is both humane and legally compliant.
Why DIY Exclusion Tends to Create New Problems
Hardware store foam sealants, wire mesh patches, and one-way exclusion funnels purchased without professional guidance are frequently applied incorrectly and defeated quickly by a determined squirrel. Sealing an entry point without first confirming the attic is completely vacated is one of the most common mistakes homeowners make, and it results in an animal trapped inside the structure that will cause significantly more damage attempting to exit than it would have otherwise.
Improperly installed exclusion materials also tend to create new vulnerabilities. A sealed vent that forces a squirrel to seek an alternative entry point may result in damage to a section of the roof that was previously intact. Action Pest conducts thorough assessments of the full roofline and attic before any exclusion work begins, ensuring that every potential vulnerability is identified and addressed as part of a complete resolution rather than a partial one.
Protect Your Attic Before the Next Breeding Season
If you have heard movement in your attic, noticed displaced soffit panels, or observed squirrels repeatedly accessing your roofline, the appropriate response is a professional inspection before the situation develops further. Action Pest provides humane squirrel removal and exclusion services across Hamilton, Burlington, Oakville, and surrounding communities, with immediate response available seven days a week.
With industry-leading guarantees, competitive pricing, and quote matching, Action Pest delivers wildlife solutions that address the problem completely and prevent recurrence. Call 905.318.1242 or visit actionpest.ca to schedule your attic inspection today.
