Spiders in Your Home? Here's Why Spraying Baseboards Never Fixes It (An Ontario Exterminator Explains)

Seeing spiders repeatedly in the same corners of your home almost always means you have an active insect food source they're hunting, plus undisturbed entry points like foundation gaps, weep holes, or window frames they're using to get in. Killing the spiders you can see does nothing unless you close the entry points, treat the wall voids they're actually living in, and remove what's feeding them. That's the part most treatments skip.

Why You Keep Seeing Spiders After "Treating" for Them

I've walked into dozens of Durham and York Region homes where the owner already tried a store-bought spray or a one-visit service. The spiders were gone for a week, then back in the same corner of the basement.

Here's the pattern I see almost every time:

• The technician sprayed visible webs and baseboards, but never injected pesticide into the wall void where the spiders and their prey were actually nesting.
• No one addressed the insect population (moths, flies, silverfish) the spiders were actually hunting.
• Egg sacs tucked behind furniture, in window tracks, or in wall voids were never located or removed.
• Exterior harborage — woodpiles, dense shrubs against the foundation, unsealed vents — kept feeding new spiders inside.

A spider infestation is a symptom of a bigger gap in the structure. Spraying the surface where you found the spider treats the sighting, not the cause — and the cause is almost always sitting inside a void you can't see.

Which Ontario Spiders Actually Matter (And Which Don't)

Most spider calls I get are for house spiders, wolf spiders, or cellar spiders — none of which pose a real health risk. But I still identify every species on a job because a small number do matter.

The only spider in Ontario with genuinely medically significant venom is the northern black widow, which is rare and restricted to extreme southern Ontario, primarily the Niagara Peninsula and the Carolinian forest zone. The yellow sac spider is the species most likely to bite Ontario homeowners unprovoked and is responsible for the majority of reported spider bites in the province, though the bite is not medically dangerous.

According to Health Canada, although nearly all spiders have venom glands, they rarely bite humans, and only a few species like the black widow can have a venomous — but not usually fatal — bite. If you are bitten and you're unsure of the species, remain calm, get medical attention right away, and apply an ice pack directly to the bite area to relieve swelling and pain.

What Complete Spider Elimination Actually Looks Like

Most companies spray the baseboards and leave. The wall voids are never touched, egg sacs are never located, and the insects the spiders were feeding on are never addressed — so two weeks later you're back to square one. Here's what I do differently on every spider job, broken into the actual separate steps, not one blur of "spraying":

1. Inspect first, spray second. I check foundation cracks, weep holes, window and door frames, attic vents, and any wall voids with visible webbing or egg sacs.
2. Treat the exterior perimeter. A residual barrier spray goes around the full exterior of the home — foundation, door and window frames, vents, and any other entry point — formulated to stay active for a full 90 days, not just kill on contact.
3. Treat the interior entry points, where needed. If activity or entry points are found inside, a matching interior residual spray is applied along baseboards, window tracks, and other access points — again, active for a full 90 days, not a one-time knockdown.
4. Inject pesticide dust directly into the wall void, when that's where the activity actually is. Where spiders are coming from inside a wall, I inject a labeled dust or aerosol pesticide through an existing gap — an outlet plate, a weep hole, a small drilled access point — so the product sits where the spiders and their prey actually travel, not just on the drywall surface they crawl past.
5. Remove egg sacs by hand where I find them. Chemical treatment doesn't reliably destroy an intact sac; physical removal does.
6. Address the food source. If moths, flies, or other insects are drawn to exterior lighting or getting in through the same gaps, that gets flagged and treated too — otherwise spiders just repopulate.
7. Use Health Canada-approved products at full label rate, especially in void work. Void treatments rely on the pesticide staying active for weeks inside a space you can't see or re-check easily, so I never dilute for speed — the product is applied at the concentration and volume the label specifies, which is also what keeps it safe around kids and pets once dry on accessible surfaces.

All AstraHive Pest Control products are Health Canada approved and safe for households with children and pets once treatments have dried.

What It Costs and What's Included

Spider treatments through AstraHive start at $250 CAD. Every job includes a full exterior perimeter residual spray and an interior residual spray along baseboards and entry points, both effective for a full 90 days, plus void injection and access-point sealing where the infestation warrants it. Homes with confirmed wall-void activity take more work to treat properly than a baseboard spray, because it means drilling or accessing the void, injecting pesticide correctly, and sealing the access point afterward — but that's the work that actually stops the problem instead of just hiding it for a week.

Every job includes:

• Same-day service in most cases, with call-backs within 5 minutes of your call or text — reach us directly at 905-925-8427
• A full interior and exterior inspection, not just a spray-and-go
• Exterior perimeter and interior residual spray treatments, both effective for 90 days
• Void treatment where activity warrants it, not just surface spraying
• A 90-day warranty — if spiders come back within that window, so do we, at no extra charge

We've been licensed by the Ontario Ministry of the Environment, Conservation and Parks since founding the company in 2015, and we currently hold a 5.0-star rating across 150+ Google reviews from homeowners across Durham, York, Peel, Simcoe County, and the wider GTA (75+ cities).

Prevention: Reducing Spiders Without a Full Treatment

If you're not yet at infestation level, a few habits go a long way between visits:

• Seal gaps around foundation vents, window frames, and utility penetrations — spiders exploit anything wider than a few millimetres.
• Switch exterior lighting to warm/yellow bulbs; white and blue-toned lights attract far more flying insects, which in turn attract spiders.
• Vacuum corners, closets, and window tracks every 2-3 weeks to remove egg sacs before they hatch.
• Keep firewood and dense vegetation at least 12-18 inches off the foundation wall.

Prevention slows things down, but if you're already seeing repeat activity in the same spot, it usually means there's an established void or entry point behind the wall, and a proper inspection with pesticide void treatment is the faster fix. Call or text 905-925-8427 if that sounds like what's happening at your place.

Why Choose AstraHive

• Licensed & Insured: Certified by the Ontario Ministry of Environment, Conservation and Parks.
• Fast response: Same-day service available, with a callback within 5 minutes.
• 100% Satisfaction Guarantee: If pests come back, we re-treat at no additional charge.
• Proven track record: 5.0 stars on Google across 150+ reviews.
• Family & pet safe: Health Canada approved products on every job.

Frequently Asked Questions

Are the spiders in my Ontario home dangerous?

In the vast majority of cases, no. Most spiders found in Ontario homes are house spiders, cellar spiders, or wolf spiders, none of which pose a health risk to people. The one exception to watch for is the northern black widow, which is rare and mostly confined to the Niagara Peninsula and Carolinian forest zone in extreme southern Ontario.

Why do spiders keep coming back after I spray them myself?

Store-bought sprays only kill the spider you can see, not the egg sacs, wall voids, entry points, or insect food source drawing new spiders in. Unless the void behind the wall is treated with the right pesticide, the actual gap they're using to get inside is sealed, and the insects they're hunting are addressed, new spiders will keep replacing the ones you killed within days.

What should I do if I'm bitten by a spider in Ontario?

Stay calm, wash the area, and apply an ice pack to reduce swelling and pain, then seek medical attention if you notice worsening symptoms, muscle cramping, or nausea. These are the same first steps recommended by Health Canada, since severe reactions are rare but should still be checked by a doctor, especially in children or the elderly.

How much does professional spider control cost in Ontario?

Through AstraHive Pest Control, spider treatments start at $250 CAD. That price includes a full inspection, an exterior perimeter residual spray and an interior residual spray (both effective for 90 days), void injection where warranted, and a 90-day warranty covering free re-treatment if spiders return.

How fast can an exterminator come out for a spider problem?

AstraHive offers same-day service in most cases across Durham, York, Peel, Simcoe County and the GTA, and calls to 905-925-8427 are returned within 5 minutes. Fast response matters with spiders because delaying treatment gives egg sacs more time to hatch inside wall voids, which can turn a single sighting into a recurring problem.

Sources

• Health Canada — Nearly all spiders have venom glands but rarely bite humans, and only a few species like the black widow have a venomous but not usually fatal bite; if bitten, seek medical attention and apply an ice pack.
• Ontario Spider Squad (Ontario Spider Identification Guide) — The northern black widow is the only medically significant venomous spider in Ontario and is rare, restricted mainly to the Niagara Peninsula and Carolinian forest zone; the yellow sac spider causes most reported bites in the province but is not medically dangerous.
• CBC News — Medically serious spider bites are rare in Canada, and the black widow is the only spider in the country that typically poses a significant risk.

Areas We Serve

AstraHive Pest Control proudly serves 75+ communities across the following regions:

• Toronto: Toronto, North York, Scarborough, Etobicoke, East York, York, Leslieville, Lakeview
• Durham Region: Oshawa, Whitby, Ajax, Pickering, Clarington, Bowmanville, Courtice, Newcastle, Port Perry, Brooklin, Uxbridge, Scugog, Brock, Seaton
• York Region: Vaughan, Markham, Richmond Hill, Aurora, Newmarket, Thornhill, Woodbridge, Kleinburg, Maple, Stouffville, Unionville, Keswick, Holland Landing, East Gwillimbury, Georgina, King City, King Township, Nobleton, Berczy Village, Cathedraltown, Commerce Valley, Cornell, Wismer, Whitchurch-Stouffville, Sutton, Schomberg
• Peel Region: Mississauga, Brampton, Caledon, Malton, Port Credit, Streetsville, Meadowvale, Cooksville, Bolton, Palgrave
• Extended Service Area: Peterborough, Lindsay, Port Hope, Barrie, Bradford, Innisfil, Collingwood, Wasaga Beach, Orillia, Burlington, Oakville, Milton, Hamilton, Grimsby, St. Catharines, Welland, Niagara Falls

Don't see your city listed? Call us — we likely cover it.