# Fall Spiders in Ontario — Spider Squad

## Why Fall Is the Worst Spider Season

August through October is the peak of spider visibility and indoor encounters in Ontario. This is not a coincidence — it's predictable biology.

**Spiders reach adult size in late summer.** Most Ontario spiders complete their primary growth phase by late August. Juveniles that were too small to notice through spring and early summer are now fully grown and much more visible.

**Males wander seeking mates.** Many spider species — particularly house spiders, wolf spiders, and funnel weavers — have males that roam actively in search of females in late summer and fall. These wandering males appear in open areas, on floors, in unexpected locations. They're not building webs or settling — they're moving through your space.

**Cooling temperatures drive movement toward structures.** As nighttime temperatures drop, spiders move toward the warmth of buildings. They're not seeking you — they're seeking heat differentials and the shelter of structures, which concentrate them around foundations and entry points.

**Egg-sac season.** Females of many species produce egg sacs in fall for overwintering. This biological imperative increases their feeding and therefore activity levels.

## Species Driving the Fall Rush

**House spider (Parasteatoda tepidariorum):** Males wander September through October. Often found in open areas, bathtubs, sinks (having fallen in and unable to climb the smooth surface).

**Wolf spider (Lycosidae):** Large, fast, ground-level. Highly visible in fall. Mature adult females carrying eggs on their back are particularly alarming. They enter through door gaps and ground-level openings.

**Orb weaver spiders (Araneidae):** Reach maximum size in August to September. Their large, prominent circular webs across exterior eaves, doorways, and garden spaces are at their most visible in fall. They are primarily outdoor spiders.

**Funnel web spiders (Agelenidae):** Build sheet-like funnel webs in grass, mulch, and under shrubs. Very active in fall.

## When to Act

The optimal time to address fall spider pressure is **before** it peaks — a late August treatment (mid-August to early September) applies the exterior barrier while it has maximum time to work before fall activity peaks. Residual duration of 30 to 90 days means an August treatment covers through October.

If you're already in fall and noticing high activity, treatment is still effective — it reduces ongoing pressure and begins eliminating existing populations immediately.

## What a Fall Treatment Covers

Standard exterior perimeter treatment: foundation, window frames, door frames, soffits, eaves — the full perimeter barrier. Targets wandering spiders crossing treated zones and web-building spiders establishing on treated surfaces.

If indoor activity is high (wolf spiders in the basement, house spiders throughout the main floor), interior spot treatment can be added.

To book: call 905-935-7498 or request a quote at spidersquad.ca.