Bug Identifier

Spiders

Common House Spider

Parasteatoda tepidariorum

0246810
Body length in millimeters. Shaded bar shows the typical adult range.
Scientific nameParasteatoda tepidariorum
GroupSpiders
Size4–8 mm (up to about 0.31 in)
Colors Brown, Tan and Gray
Legs8 legs
WingsNo (as usually seen)
Where foundIndoors, anywhere and Basement or garage
Most activeSpring, Summer, Fall and Winter
BitesNo
StingsNo
Risk levelHarmless

How to identify it

The common house spider is a small member of the spiders group. Eight legs, two body sections and silk-spinning organs at the rear. Check for these three features:

  1. Round, mottled brown abdomen with chevron markings
  2. Tangled, irregular cobwebs in upper corners
  3. Legs banded with lighter and darker rings

About this bug

A small, brownish spider that builds tangled cobwebs in corners, windows and basements. It is the web-builder most often seen inside North American homes.

You'll usually find common house spiders indoors and in basements and garages. They are most active in spring, summer, fall and winter.

Is it dangerous?

Common house spiders are harmless and help catch flies and other indoor pests.

Our rating: Harmless, meaning it poses no real threat to people, pets or property.

When you'll see common house spiders

Common House Spiders are most active in spring, summer, fall and winter. In spring, overwintering adults become active and many species lay their first eggs. Summer heat speeds up development, so populations can grow quickly. In fall, many bugs look for shelter, and some move toward or into buildings. In winter, activity continues mainly indoors in heated spaces.

Typical places to check: indoors, anywhere and basement or garage.

About spiders

The common house spider is one of the spiders. Spiders have eight legs, two main body sections and no antennae. Almost all spiders have venom to subdue prey, but only a few have venom that matters to people. Many build webs, while others, such as wolf spiders and jumping spiders, hunt on foot.

Spiders go where their food is. A home with lots of spiders usually has plenty of other insects, so general pest control reduces spiders too.

Should you get rid of it?

No control is needed. Common House Spiders are not pests, and many help by eating other insects or pollinating plants. If one is indoors, move it outside with a cup and a sheet of paper.

Bugs that look similar

Black Widow SpiderLatrodectus mactans3–13 mmHealth risk

Size: Black Widow Spiders are larger, reaching 13 mm, while common house spiders top out around 8 mm.

Cellar SpiderPholcus phalangioides7–10 mmHarmless

Size: Cellar Spiders are larger, reaching 10 mm, while common house spiders top out around 8 mm.

Spotted OrbweaverNeoscona crucifera7–15 mmHarmless

Size: Spotted Orbweavers are larger, reaching 15 mm, while common house spiders top out around 8 mm.

Frequently asked questions

What does a common house spider look like?

Round, mottled brown abdomen with chevron markings. Adults measure 4–8 mm (up to about 0.31 in).

Does the common house spider bite or sting?

It does not bite. It does not sting. Common house spiders are harmless and help catch flies and other indoor pests.

Where do common house spiders live?

Common House Spiders live indoors and in basements and garages.

When are common house spiders most active?

Mostly in spring, summer, fall and winter.