# Basement Spiders — Spider Squad

## Why Basements Concentrate Spiders

Basements are ideal spider habitat: dark, low-traffic, relatively humid, sheltered from weather, and typically adjacent to entry points from the outside (foundation gaps, floor drains, window wells, pipe penetrations). This combination means even a modest exterior spider pressure often results in noticeable basement accumulations.

## Common Basement Spider Species in Ontario

**Cellar spider (Pholcus phalangioides):** The most common. Long-legged, pale grey, hangs upside-down in loose webs in corners, around pipes, along the ceiling. They cluster and accumulate — dozens in a single unfinished basement area is not unusual. Completely harmless.

**House spider (Parasteatoda tepidariorum):** Builds tangled cobwebs in undisturbed basement areas. Common around utility equipment, storage shelves, and along the top of foundation walls.

**Wolf spider:** Ground-level hunter. Enters through floor-level gaps, window wells, and any ground contact entry. Alarming due to size but not dangerous. Seen on basement floors and walls rather than in webs.

**Funnel web spider (Agelenidae):** Builds flat, sheet-like webs in corners and across the floor in undisturbed areas. Common in unfinished basements with ground contact or crawl space connections.

**Yellow sac spider:** Found in basements when they move indoors in fall. Look for silk tube retreats in corners, behind stored items, and along the top of concrete walls.

## How They Get In

The main entry routes for basement spiders:
- Foundation cracks and gaps (especially where different materials meet)
- Floor drain openings
- Basement window frames (even small gaps in weatherstripping)
- Window wells that accumulate debris and provide harbouring habitat
- Gaps around pipe and wire penetrations through the foundation wall
- Crawl space connections (if the basement has a crawl space adjacent to it)
- Garage-to-basement door gaps (if attached garage)

## Why There Are So Many

Basements provide abundant food: drain flies, fungus gnats, silverfish, centipedes, and other insects that thrive in damp, undisturbed conditions. Fix the insect pressure and you reduce the spider pressure automatically.

Address: any standing moisture, clogged floor drains, leaking pipes, inadequate ventilation (high humidity), and cardboard box accumulation (food and harbouring sites for insects).

## Treatment Approach

**Exterior:** The perimeter barrier (foundation, window frames, eaves) reduces spiders migrating from outside. This handles a significant portion of basement pressure for most homes.

**Interior (when needed):** For established basement populations — particularly large cellar spider clusters, active wolf spider presence, or yellow sac spider concentrations — interior spot treatment applied to basement walls, corners, pipe areas, and under-stair voids is more directly effective. Interior treatment is added to any booking on request.

**Web cleanout:** Removing existing webs (and egg sacs) from the basement before treatment eliminates the harbouring residue and gives you a clean baseline.

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