Red house spiders are a common sight in Canadian homes, particularly in Ontario. These reddish or brownish-colored arachnids often cause concern due to their striking appearance, leading many homeowners to wonder if they are dangerous. While most red spiders in Canada are harmless, some can deliver a mild bite if threatened. This guide covers everything you need to know about canada red spiders, including their identification, behavior, potential risks, and effective pest control methods.
What Is a Red House Spider?
The term “red house spider” typically refers to several species of spiders that have reddish, brownish, or orange hues. In Canada, the most common species include:
- Red-spotted ant mimic spider (Castianeira descripta) – A dark spider with reddish markings that mimics ants.
- Woodlouse spider (Dysdera crocata) – A reddish-orange spider with large fangs, often found under rocks and logs.
- Common house spider (Parasteatoda tepidariorum) – Sometimes appears with reddish-brown coloring.
These spiders are usually small to medium-sized, ranging from 5–15 mm in body length. They are often found in basements, garages, and dark corners of homes where they hunt for insects.
Are Red House Spiders Poisonous?
Most red spiders in Canada are not medically significant, meaning their venom is not harmful to humans. However, some species, like the woodlouse spider, can deliver a painful (but non-dangerous) bite if handled roughly.
Signs of a Red House Spider Infestation
- Visible spiders (especially in dark, undisturbed areas)
- Webbing in corners, basements, or attics
- Egg sacs (small, silken balls attached to surfaces)
Where Do Red House Spiders Live?
Spiders prefer warm, sheltered environments, making homes an ideal habitat. Common hiding spots include:
- Basements and crawl spaces
- Behind furniture and baseboards
- Garages and sheds
- Under eaves and window frames
They are most active at night, hunting for small insects like flies, ants, and other spiders.
How to Prevent Red House Spiders
Since house spiders enter homes in search of prey, reducing their food sources and entry points is key to prevention.
1. Seal Entry Points
- Install weather stripping on doors and windows.
- Repair cracks in walls and foundations.
- Use window screens to keep spiders out.
2. Reduce Clutter
- Eliminate piles of boxes, newspapers, and clothing where spiders hide.
- Keep storage areas clean and organized.
3. Control Other Pests
- Since spiders feed on insects, managing ants, flies, and mosquitoes reduces their food supply.
4. Natural Repellents
- Peppermint oil, vinegar, or citrus sprays can deter spiders.
- Diatomaceous earth (food-grade) can be sprinkled in spider-prone areas.
5. Professional Pest Control
If you have a persistent spider problem, BP Pest Control offers effective spider removal and prevention services in Ontario.
BP Pest Control
House spiders are common in Canadian homes but are generally harmless and beneficial as they control other pests. While they may look intimidating, most species pose no real threat to humans. By keeping your home clean, sealing entry points, and reducing insect populations, you can minimize spider activity.
For expert spider control in Ontario, visit BP Pest Control for safe and effective removal services.
FAQs About Red House Spider in Canada
Are red house spider dangerous?
Most house spiders in Canada are not dangerous to humans. Their bites, if they occur, are usually mild and cause only minor irritation.
What does a red house spider look like?
They vary in color from reddish-brown to orange and are typically small to medium-sized (5–15 mm). Some have striped legs or spotted abdomens.
Where are red house spiders commonly found in homes?
They prefer dark, undisturbed areas like basements, attics, garages, and behind furniture.
Do red house spiders bite?
Yes, but they rarely bite unless threatened. A bite may cause mild redness or itching, but severe reactions are uncommon.
How do I get rid of red house spiders naturally?
- Use essential oils (peppermint, tea tree, or citrus).
- Keep your home clean and clutter-free.
- Use a vacuum to remove spiders and webs.
Are there poisonous red spiders in Ontario?
Ontario has no highly venomous red spiders. The closest is the woodlouse spider, which can bite but is not medically dangerous.
Why do I have red spiders in my house?
They enter homes seeking shelter and prey (other insects). Reducing other pests can help deter them.
How can I keep spiders out of my house?
- Seal cracks and gaps.
- Reduce outdoor lighting (which attracts insects, their food source).
- Use spider repellents like vinegar sprays.
What’s the difference between a red house spider and a brown recluse?
Brown recluses are not native to Canada and have a violin-shaped marking. Red spiders in Canada are not the same and are far less dangerous. Should I call a pest control expert for spiders?
If you have a large infestation or are dealing with frequent sightings, professional pest control (like BP Pest Control) can provide long-term solutions.
How does sealing cracks and gaps help prevent red house spiders?
Sealing cracks around windows, doors, and foundations is one of the most effective ways to keep red house spiders out. These small openings serve as entry points for spiders and the insects they hunt. Use caulk, weather stripping, or expandable foam to seal gaps larger than 1/4 inch.
What is Nesticodes rufipes (the red house spider)?
Nesticodes rufipes, commonly called the house spider, is a small reddish-brown spider often found indoors. While it builds messy webs in corners, it’s not considered dangerous to humans. This species is sometimes confused with more venomous spiders but poses minimal risk in Canadian homes.
What do red house spiders eat?
Red house spiders primarily feed on:
- Small insects like flies, mosquitoes, and ants
- Other spiders
- Occasionally, they may eat pollen or organic debris caught in their webs
Eliminating their food sources by controlling other pests will help reduce spider populations.
Why do red house spiders build webs in my home?
Canada house spiders spin webs to:
- Catch flying and crawling insects
- Create sheltered nesting areas
- Establish territory in undisturbed corners
Regular cleaning and web removal discourages them from settling in.
Are all red-colored spiders in houses dangerous?
No. While their bright color alarms many homeowners, most red spiders in Canada (including Nesticodes rufipes) have mild venom. Only two medically significant spiders exist in Canada (black widow and brown recluse), and neither are bright red.
How can I identify a true red house spider?
Look for these characteristics:
- Reddish-brown or orange body (females darker than males)
- Small size (5-10mm body length)
- Round abdomen with possible faint markings
- Messy, tangled webs in upper corners
What’s the difference between a red house spider and a woodlouse spider?
While both are reddish, key differences include:
- Red house spider: Builds webs, smaller fangs, harmless
- Woodlouse spider: Hunts without webs, large prominent fangs, can deliver painful (but not dangerous) bite
Do red house spiders live in groups?
Unlike some spider species, house spiders are solitary. You may find multiple individuals in one area if there’s abundant food, but they don’t form colonies.
How long do red house spiders live?
The typical lifespan is:
- 1-2 years for females
- Several months for males (who die after mating)
- Spiderlings take about a year to mature
When are red house spiders most active in Canada?
Peak activity occurs:
- Indoors: Year-round in heated homes
- Outdoors: Late spring through fall
- Most visible at night when hunting
Can red house spiders survive Canadian winters?
Indoors, yes – heated homes allow year-round activity. Outdoors, only eggs and some sheltered adults survive freezing temperatures.
What natural predators control red house spiders?
Common predators include:
- Other larger spiders
- Centipedes
- Certain wasp species
- Occasionally birds that find them indoors
Are red house spider webs dangerous?
The webs themselves pose no risk, though some people may be allergic to certain spider silk proteins. The main concerns are:
- Aesthetic issues from messy webs
- Potential for spider bites when cleaning (rare)
How can I safely remove red house spiders?
Effective removal methods:
- Vacuuming webs and spiders
- Using a glass and paper to capture/release outdoors
- Dusting corners with diatomaceous earth
- Installing sticky traps in problem areas
Should I worry about red house spider bites?
Bites are uncommon and generally:
- No worse than a mild bee sting
- May cause slight redness/itching
- Rarely require medical attention
- Only occur when the spider is pressed against skin
For persistent infestations or bite concerns, professional pest control services like BP Pest Control can provide safe, effective solutions.