# Ontario Spider Identification Guide — Spider Squad

Ontario has hundreds of spider species, but a small number account for the vast majority of home encounters. This guide covers the species most commonly found in and around Ontario homes.

## Quick Identification by Behaviour

**Web-building in corners, eaves, windows:** House spider, cellar spider, cobweb spider
**Large webs in garden/eaves in late summer:** Orb weaver spiders
**Ground-level, fast-moving, no web:** Wolf spider
**Small, quick, near windows and sunny walls:** Jumping spider
**Near water or docks:** Dock spider (fishing spider)
**Thin, pale spider in webs near ceiling or corners:** Cellar spider
**Small, yellow-ish, near windows or trim:** Yellow sac spider

## Species in This Guide

**Common indoor/exterior:**
- House spider (Parasteatoda tepidariorum) — most common Ontario house spider
- Cellar spider (Pholcus phalangioides) — the "daddy long-legs" that clusters in basements
- Wolf spider (Lycosidae) — large, ground-hunting, often mistaken for brown recluse
- Jumping spider (Salticidae) — compact, furry, excellent eyesight
- Yellow sac spider (Cheiracanthium) — small, pale, builds silk tube retreats

**Seasonal/outdoor:**
- Orb weaver spider — builds the classic circular webs, peaks in late summer
- Dock spider / fishing spider (Dolomedes) — very large, near water

**Watch list:**
- Black widow (Latrodectus variolus) — rare but present in parts of southern Ontario
- Brown recluse (Loxosceles reclusa) — not established in Ontario; commonly misidentified

## Are Ontario Spiders Dangerous?

The vast majority of Ontario spiders are harmless to humans. They are physically capable of biting but almost never do so unless directly threatened or compressed against skin. Wolf spiders, house spiders, and jumping spiders — the most common — have venom that may cause a localized reaction comparable to a bee sting in sensitive individuals, but serious effects are extremely rare.

The two species that warrant caution in Ontario are: the black widow (confirmed in some areas of southern Ontario, rare) and yellow sac spiders (the most likely to cause a notable bite reaction among common species, though still typically minor).

Brown recluse spiders are not established in Ontario. A "brown recluse bite" reported in Ontario is almost always a wound from another cause.

## Why They're in Your Home

Spiders follow their food — and insects follow light, warmth, and moisture. Exterior lighting, gaps around windows and doors, moisture in basements, and insect-attracting plants near the foundation are the primary reasons spiders concentrate around homes.

For species-specific detail, visit the individual pages linked from the main Spider ID guide or the navigation menu.