How to Keep Spiders Out of Your Montreal Home: Prevention Guide

Spiders are the most common pest concern for Montreal homeowners — and for good reason. Unlike ants or cockroaches that stay mostly hidden, spiders make themselves visible with webs in corners, basements, and window frames. The good news: spider prevention is largely within your control. By understanding what attracts spiders and how they enter, you can dramatically reduce spider populations in your home without relying on constant chemical treatments.

Why Spiders Choose Your Home

Spiders need three things: shelter, humidity, and food (other insects). Montreal homes provide all three, especially older properties with stone foundations, unfinished basements, and plenty of cracks and crevices for hiding. Understanding these attractants is the first step to effective prevention.

Seal Entry Points: The Foundation of Prevention

Spiders enter through gaps as small as 3mm. A thorough inspection and sealing program is the single most effective prevention measure. Focus on these common entry points:

• Gaps around window frames and door thresholds — install weatherstripping and door sweeps
• Foundation cracks and gaps where utilities enter — seal with caulk or expandable foam
• Vents and weep holes — cover with fine mesh screens (insect mesh, not standard hardware cloth)
• Gaps under siding and around soffits — these are superhighways for spiders seeking attics
• Window wells — ensure covers fit tightly and drain properly
• Chimneys — install chimney caps with mesh sides

Reduce Exterior Lighting

Outdoor lights are spider magnets — not because spiders are attracted to light, but because lights attract the flying insects that spiders eat. A single porch light can support dozens of spiders on the surrounding walls and eaves. Reduce this attractant:

• Switch to yellow "bug lights" or warm LED bulbs (2700K) — these attract fewer insects
• Install motion sensors so lights are only on when needed
• Position lights away from the house, shining toward entry areas rather than mounted on the house itself
• Turn off decorative lighting when not needed

Eliminate Harborage Around the Foundation

Spiders hide in debris during the day and hunt at night. The zone immediately around your foundation should be clear of spider habitat:

• Remove leaf litter, mulch, and organic debris from within 30cm of the foundation
• Trim shrubs and bushes so they do not touch the house — spiders use them as bridges
• Store firewood at least 6 metres from the house and elevate it off the ground
• Eliminate rock piles, lumber stacks, and stored items near the foundation
• Keep grass mowed short near the house perimeter

Control Indoor Humidity

Spiders prefer humid environments. Montreal basements are particularly attractive to cellar spiders and other moisture-loving species. Reduce humidity to make your home less hospitable:

• Run a dehumidifier in basements, targeting 40–50% relative humidity
• Fix leaky pipes and ensure proper drainage around the foundation
• Use exhaust fans in bathrooms and kitchens
• Ensure clothes dryers vent completely outside, not into basements or crawl spaces
• Remove cardboard boxes from basements — spiders nest in the corrugations; use plastic bins instead

Eliminate the Food Source: Other Insects

Spiders are predators. If you have spiders, you have other insects. Controlling the prey population naturally reduces spider numbers:

• Address ant problems promptly — ants are a major spider food source
• Install screens on windows and repair damaged screens immediately
• Use yellow bug lights outdoors to reduce flying insect attraction
• Keep kitchen counters clean and food sealed to avoid attracting prey insects
• Consider exterior perimeter insecticide treatments to reduce the overall insect population

Regular Web Removal

Removing webs serves two purposes: it eliminates egg sacs (preventing the next generation) and forces spiders to relocate. Make web removal part of your routine:

• Inspect and remove webs weekly during spider season (August–October)
• Use a vacuum with a hose attachment for corners and high areas
• Pay special attention to basements, garages, and storage areas
• Check window frames, door frames, and ceiling corners
• Remove outdoor webs from eaves, porches, and exterior walls

When to Call a Professional

DIY prevention measures are highly effective for minor spider issues. However, call Blackline Pest Control if:

• You are seeing multiple spiders daily despite prevention efforts
• Spiders are appearing in living areas, not just basements
• You find egg sacs throughout the home — this indicates an established population
• You are unsure whether spiders are dangerous species
• Spider populations spike suddenly — this often indicates an underlying insect infestation

Our spider treatment program includes exterior perimeter spray, interior crack-and-crevice treatment, web removal, and identification of entry points that need sealing. We also address the underlying insect population that attracts spiders. Call 514-809-1999 for a free inspection.