Spider identification
Almost every large brown spider that runs across a floor in September gets called a wolf spider, and often that is right. Wolf spiders are ground hunters that live under the mulch, the deck and the stones all summer and come in under the door when the nights turn cold. They look worse than they are.
Hairy and brown with darker stripes down the head and body, stout legged and fast, from 0.5 cm in small species to 2.5 cm in the body in the largest. Eight eyes in three rows, with two large ones at the front that reflect a flashlight at night. No web. The surest tell is the female: she carries a round egg sac attached to the rear of her body, and later carries dozens of spiderlings on her back.
On the ground: under mulch, stones, woodpiles, the deck, the bottom step and in the lawn and garden beds. They hunt on the surface at night. In September and October they move toward warmth and come in under door sweeps, through garage doors and up through basement window wells, and are found on basement floors, in bathtubs and along baseboards.
Outdoors all season. The indoor calls start in September when the nights cool and run to the first hard frost. Adults overwinter under cover and in the leaf litter; they do not breed indoors.
Only if squeezed or trapped against skin, for example under a hand on the floor. It is a brief local pain like a bee sting with no lasting effects. The old reports of flesh destroying wolf spider bites came from South America and have been discredited. Most "spider bites" in Ontario are never confirmed; see the bite section of our guide to common spiders in Ontario for what a real one looks like.
Wolf spiders are not web builders, so there is nothing to vacuum off the house; what we do is treat the places they enter. On a visit we check and treat the foundation line, the base of door frames, the garage door track and the basement window wells where the exterior meets the ground, which is where the fall movement comes through. The fix that lasts is physical: a new sweep on the exterior doors, weatherstripping on the garage door, and mulch and firewood pulled back from the foundation. We will tell you where the gaps are. Every visit ends with a written summary of what we found and where product was applied, if any. Our spider control service and 60 day guarantee pages have the details and pricing.
Dark fishing spider, Grass spider, Barn funnel weaver. The dark fishing spider is bigger and lives on docks and boathouse walls; its female carries the egg sac in her jaws, not behind her. Grass spiders sit in sheet webs and have long spinnerets. The barn funnel weaver is the big brown basement spider that lives in a funnel web in the corner and does not wander the floor. The full list with photos is in the common spiders in Ontario guide.
Good to know
They are moving toward warmth as the nights cool and coming in under door sweeps and garage doors. They are not breeding inside, and the movement stops with the first hard frost.
No. A bite is rare and comparable to a bee sting. They are shy and run when disturbed.
A treated foundation line and door threshold helps during the fall movement, but a new door sweep does more and lasts longer. We treat the entry points on a visit and tell you where the gaps are.
Related guides: Preparing your home for spider season, Keeping spiders away from windows, eaves and lights. Service areas where this spider is found: Sarnia and Bright's Grove, Goderich, Kincardine, Port Elgin.
