Common House Spider (Parasteatoda tepidariorum) — identification, habitat & look-alikes

The common house spider is a small spider that makes messy s in corners, windows, basements, and sheds across much of the United States. Its rounded abdomen has variable gray, brown, white, and black markings, and it catches many kinds of small creatures found around homes.

Appearance

Appearance: Females are about 3/16–1/3 in (5–8 mm) long, while males are usually near 1/8 in (4 mm). The abdomen is rounded and mottled gray to brown with white and black marks, and the yellow-brown legs have dark rings.

Look-alikes

triangulate combfootSteatoda triangulosa

The triangulate combfoot has a row of pale triangular marks down its brown abdomen. The common house spider usually has a more irregular marbled pattern with white and black chevrons.

Why they get mixed upBoth are small cobweb spiders that live in dark corners of buildings.

Where it lives

Typical habitats: building corners
basements and crawl spaces
sheds and barns
Range: It occurs through most of the contiguous United States and has been carried by people to much of the world.
Preferred conditions: It favors protected places around buildings, including window frames, eaves, bridges, and culverts.

Behavior

Diet: It catches a variety of small creatures, including flies, roaches, and other household pests.
Activity: It hangs in an irregular cobweb and waits for prey, often near the middle of the web. It may abandon one web and build another nearby.

Life cycle

Breeding season: Adults and young can be found indoors throughout the year.
Reproduction: The female hangs brown, papery egg sacs in her web, often making several sacs during her life.

Cautions

Cautions: It is not considered medically important and rarely bites people. Avoid handling any spider with bare hands.

Conservation

IUCN Red List: NENot EvaluatedNot yet assessed

Culture and stories

Culture and stories: Its abandoned webs are a common source of dusty cobwebs in buildings.

11 sources