A big brown spider darting across the basement floor in the fall is almost always a wolf spider or a house spider. Both groups are common in homes in and around Montreal. The good news: neither is considered a health hazard in Quebec.
At a glance
- Wolf spider (family Lycosidae): stocky body, brown or grey, often striped; body length from under 1 cm to about 2.5 cm depending on the species. It hunts on the ground, without a web.
- House spider (genera Tegenaria and Eratigena): brown body about 6 to 18 mm long, long hairy legs, sheet web ending in a funnel.
- They're mostly seen in the basement, on the ground floor and in the garage, from late summer into fall.
- Bites are rare, only if the spider is pressed against the skin; the effect is local and temporary, and no disease is transmitted.
How to recognize it
The wolf spider is stocky and hairy. Its back often has paler stripes on a brown, grey or black background. Its eyes are arranged in three rows; two large forward-facing eyes are easy to see up close. It doesn't spin a web to hunt: it runs along the ground and chases down its prey. The female drags her egg sac attached to the tip of her abdomen, then carries her young on her back after they hatch.
The house spider is slimmer, with long, very hairy legs, often ringed with grey. It lives in a horizontal sheet-like web that ends in a tube where it waits for prey. The name "house spider" covers several closely related species:
- Domestic house spider (Tegenaria domestica): body length of 6 to 11.5 mm. Introduced from Europe, it's now widespread in homes across North America.
- Giant house spider (Eratigena atrica and related species): body length of up to about 18 mm for the female, and a 4.5 cm span including the legs. Males wander through homes from July to October looking for a female.
- Hobo spider (Eratigena agrestis, formerly Tegenaria agrestis): 7 to 14 mm. It's mainly reported in western North America.
These species can only be told apart with certainty under a microscope; for practical purposes, knowing whether it's a wolf spider or a house spider is enough.
| Criterion | Wolf spider | House spider | Cellar spider (daddy long-legs) |
|---|---|---|---|
| Shape | Stocky, sturdy legs | Slim, long hairy legs | Small body, very long thin legs |
| Color | Brown, grey or black, pale stripes on the back | Brown, chevron pattern on the abdomen | Pale beige to greyish |
| Web | None for hunting | Sheet web with a funnel, in a corner near the floor | Irregular web, often on the ceiling |
Where is it found in a Montreal home?
They're mostly found in the basement, laundry room, garage and shed, and near exterior doors. The wolf spider normally lives outdoors, under stones, boards, firewood or siding. It mostly comes inside in late summer and fall, when it's looking for shelter for the winter.
The house spider settles in year-round in dark corners near the floor, behind boxes or under the stairs. It's mostly adult males, out looking for a female, that you run into in the living room or bathtub in late summer.
Lots of spiders in the basement often means lots of prey, like silverfish or woodlice drawn by the moisture. Our guide to moisture bugs helps you identify them.
Is it dangerous?
No. According to the Montreal Insectarium, spiders capable of a truly dangerous bite don't live in Quebec. Health Canada points out that spiders don't transmit disease and rarely bite, only when they feel threatened.
A wolf spider may bite if it's handled or gets trapped against the skin, in clothing or in a boot. This causes immediate pain, redness and sometimes slight swelling, which usually go away in less than 24 hours. For the domestic house spider, no bites have been documented: it's fast and shy. Larger house spiders can pierce the skin, but the reaction stays local and poses no threat to humans or pets.
If you're bitten, Health Canada advises staying calm, putting ice on the area and seeing a doctor, going to a hospital or contacting a poison control centre.
How to get rid of it
Start with these simple steps:
- Caulk the bottom of doors, around windows and foundation cracks; repair window screens.
- Vacuum corners, behind furniture and under the stairs to remove webs and egg sacs.
- Don't leave clothes, shoes or blankets on the basement floor; store boxes in closed bins.
- Keep firewood, boards and leaf piles away from the house.
- Dehumidify the basement to reduce the insects they feed on.
- For a single spider, a glass and a piece of cardboard are all you need to put it back outside.
When they keep coming back, a professional inspects before any treatment: they find entry points, web areas and the insects attracting the spiders. They then treat thresholds, cracks and the foundation perimeter with products (biopesticides and pesticides) registered by Health Canada, applied according to the label, without forgetting the insects the spiders feed on.
When to call an exterminator
Call if you find spiders every week despite cleaning, if egg sacs show up in several rooms, or if a business needs to stay spotless. See our spider extermination in Montreal page or our commercial service. The work is covered by a written guarantee and our vehicles are unmarked.
Frequently Asked Questions
Is the wolf spider venomous?
It has venom to paralyze its prey, but it isn't dangerous to humans. Its bite, which is rare, causes pain and redness that usually go away in less than 24 hours.
Can a house spider cause a wound that eats away at the skin?
No, according to current knowledge. That reputation comes from the hobo spider, found mainly in the western part of the continent. It has never been confirmed: U.S. health authorities no longer list it among venomous spiders, and there's no evidence of it in Canada.
Why do you see more spiders at the end of summer?
Adult male house spiders leave their webs from July to October to look for a female, which brings them out into the middle of rooms. Wolf spiders, on the other hand, come inside in the fall to find shelter for the winter.
How can you tell a wolf spider from a house spider?
Look at the web: the house spider lives in a sheet web with a funnel, while the wolf spider has none and runs along the ground. The wolf spider is stockier, with pale stripes on its back; the house spider is slimmer, with long hairy legs.
Seeing this insect in your home? Our certified technicians serve Montreal, Laval, the North Shore and the South Shore, 24 hours a day. Request a free quote or call (438) 835-8401.
Other identification guides: Moisture Bugs: Identifying Basement Insects · Earwigs: Identification and Solutions in Montreal · Millipedes and House Centipedes: Identification and Solutions · Woodlice in the House: Identification and Solutions · Larder Beetles and Carpet Beetles: How to Recognize Them · Weevils and Flour Beetles in the Pantry · Deer Mouse, House Mouse or Rat: How to Tell Them Apart · Biting Midges: Recognizing These Tiny Biting Insects · all the guides
