Household Spider Identification Guide for Southern Ontario

Common House Spider
(Parasteatoda tepidariorum)

• What They Look Like: Small, yellowish-brown spiders with darker markings. About the size of a nickel when fully grown.
• Where They Hide: These spiders love to set up webs in the corners of ceilings, closets, basements, and around windows.
• Why They’re Here: They’re drawn indoors by small insects that sneak into your home.
• Are They Dangerous?: No. These spiders are harmless to people, and their bites are not medically significant.

Cellar Spider

(Pholcus phalangioides)

• What They Look Like: Pale brown or grey, with very long, thin legs and a small body.
• Where They Hide: As the name suggests, they like basements, crawl spaces, and other humid areas in your home.
• Why They’re Here: They’re looking for a cool, damp place and love to feast on smaller insects.
• Are They Dangerous?: No. Despite myths, their venom poses no threat to humans.

Wolf Spider

(Hogna spp.)

• What They Look Like: Big, hairy, and fast-moving. They’re usually brown or grey with dark markings.
• Where They Hide: You’ll likely find them on the ground in basements, near doors, or close to windows where they can hunt.
• Why They’re Here: These spiders are hunters, so they’re attracted to homes with plenty of bugs.
• Are They Dangerous?: While their bite can be painful, it’s not dangerous. They’re not aggressive unless provoked.

Black and Yellow Garden Spider

(Argiope aurantia)

• What They Look Like: Beautiful black and yellow markings. They can grow large, but don’t let that scare you.
• Where They Hide: They prefer outdoor spaces like gardens or near sheds but can occasionally wander indoors.
• Why They’re Here: These spiders are drawn to areas with a lot of insects, like gardens.
• Are They Dangerous?: No. They’re harmless, and their venom won’t cause you any harm.

Brown Recluse Spider

(Loxosceles reclusa)

• What They Look Like: Light to dark brown with a violin-shaped marking on their back.
• Where They Hide: Although rare in Southern Ontario, they may be found in quiet, dry spaces like attics, storage areas, and closets.
• Why They’re Here: They prefer undisturbed areas, hiding in shoes or boxes.
• Are They Dangerous?: Yes, though rare here. Their bite can cause tissue damage and requires medical attention, but bites are extremely uncommon.

Northern Black Widow

(Latrodectus variolus)

• What They Look Like: Shiny black with a red hourglass on their abdomen.
• Where They Hide: They prefer dark, secluded spots like sheds or garages but rarely enter homes.
• Why They’re Here: They seek out quiet, undisturbed locations with access to food.
• Are They Dangerous?: Yes. Their bite can cause serious symptoms, including muscle pain and cramps, but fatalities are extremely rare. Seek medical help if bitten.

Orb-Weaving Spider

(Araneus spp.)

• What They Look Like: Typically medium to large, with rounded, patterned abdomens. Often orange or brown.
• Where They Hide: Mostly outside in gardens, but they may enter homes through open windows or doors.
• Why They’re Here: They are drawn to flying insects and build large webs in open areas.
• Are They Dangerous?: No. Orb-weavers are not aggressive, and their bite is only mildly irritating.

Jumping Spider

(Salticidae family)

• What They Look Like: Small and stocky, with a compact body and short legs. Often black or brown with white markings.
• Where They Hide: You’ll spot them near windowsills or walls where they can hunt for small insects.
• Why They’re Here: They hunt actively instead of building webs, so they’re attracted to homes with lots of insects.
• Are They Dangerous?: No. These spiders are curious but completely harmless.

False Widow Spider

(Steatoda grossa)

• What They Look Like: Dark brown or black with a rounded body, similar to the more dangerous black widow, but without the red hourglass.
• Where They Hide: They prefer dark, undisturbed areas like under furniture, in basements, or in closets.
• Why They’re Here: These spiders like quiet spots where they can build small webs to catch prey.
• Are They Dangerous?: Their bite may cause mild discomfort but is not dangerous. They are much less harmful than their black widow cousins.

Fishing Spider

(Dolomedes spp.)

• What They Look Like: Large and robust, with brown or grey coloring and lighter stripes along their body.
• Where They Hide: Often near basements, garages, or homes close to water sources like ponds or wetlands.
• Why They’re Here: They’re attracted to moist areas and places with lots of insects.
• Are They Dangerous?: No. Although large and intimidating, their bite is not harmful to humans.

Yellow Sac Spider

(Cheiracanthium inclusum)

• What They Look Like: Small to medium, pale yellow with a darker head.
• Where They Hide: They often hide in cracks, ceilings, and corners of rooms, building small sacs for protection.
• Why They’re Here: They’re drawn to warm, dry spaces where they can safely rest during the day.
• Are They Dangerous?: Their bite can cause mild irritation and redness, but it’s not dangerous.