Common House Spiders: 12 Types You Will Find Indoors

Indoor spiders fall into two groups: web builders that live in your home for their whole lives and hunters that wander in from outside. Web builders stay in corners, basements and behind furniture, while hunters roam floors and walls, often in autumn.

These are the classic household spiders that live indoors full time and build webs in quiet corners.

Common Cobweb Spider

Parasteatoda tepidariorum, often called the American house spider, is a small, round, brown or gray mottled spider found in homes worldwide. It hangs upside down in a messy, tangled web in corners, window frames and behind furniture. The University of Kentucky describes it as about nickel sized with legs spread.

Cellar Spider

Cellar spiders have tiny bodies and extremely long, thin legs, so people often call them daddy longlegs. When disturbed they shake their loose webs so fast they seem to blur. The University of California notes that their main problem is the messy webs they leave in corners.

Giant and Domestic House Spiders

The giant house spider (Eratigena atrica), also called the giant funnel weaver, of Europe and the Pacific Northwest is a large, hairy, brown spider with long legs. The Wildlife Trusts note that its leg span can reach 7.5 cm (3 in) and that males wander indoors in late summer and early autumn while looking for mates, which is why people find them in baths and sinks. The smaller domestic house spider, also called the barn funnel weaver, builds flat sheet webs with a funnel retreat in basements, garages and sheds around the world.

Hunting spiders do not live in webs and usually come inside by accident, chasing insects or looking for shelter.

• Wolf spiders: hairy, striped and fast, they run along floors and baseboards, mostly in autumn. See our wolf spider guide for more.
• Yellow sac spiders: pale yellow spiders that hunt on walls and ceilings at night and rest in small silk sacs in corners by day. They sometimes bite when trapped in clothing or bedding.
• Jumping spiders: small, fuzzy and active in daylight on sunny windows.
• Woodlouse hunters: red legged spiders with large fangs that hunt woodlice in damp basements.
• Spitting spiders: slow, spotted spiders that trap insects by spitting sticky silk over them.

Each type of indoor spider prefers a different spot, so where you find it is a strong clue to what it is.

Spiders in carpet are usually just passing through, since few species live on floors. Regular vacuuming along edges removes webs, egg sacs and the insects spiders feed on.

Many spiders in one area usually point to plenty of insects for them to eat, such as flies near windows, moths near lights or springtails in a damp basement. Fixing leaks, using a dehumidifier in damp rooms and sealing gaps cuts the insect supply, and spider numbers drop with it. A sudden rise in autumn is normal and usually fades by winter.

Most indoor spiders have bodies between 4 and 12 mm (1/8 and 1/2 in) long, but some, such as the giant funnel weaver, look much bigger because of their long legs. Size alone is a poor guide to danger, since several of the largest indoor spiders are harmless.

• Small web builders: cobweb and cupboard spiders often live about one to two years.
• Cellar spiders: can live two years or more in a quiet basement.
• Funnel weavers: females can live several years indoors.
• Hunters: wolf and sac spiders usually live about a year.

A spider in your bath is not climbing out of the drain. It usually fell in while wandering and cannot climb the smooth sides.

Only two indoor spiders in North America are of real medical concern: the black widow and the brown recluse. Even these bite rarely and usually only when trapped against skin.

• Black widow: shiny black with a red hourglass, found mainly in garages, sheds, crawl spaces and basements rather than living areas. Learn more about the black widow spider.
• Brown recluse: plain brown with a violin mark and six eyes, found in boxes, closets and attics within its south central US range. Read our guide to the brown recluse spider.
• Yellow sac spider: can give a painful but mild bite.
• False widows: London's Natural History Museum says their bites cause pain similar to a wasp sting, usually lasting a few hours.

The southern crevice weaver, also known as the southern house spider, is often mistaken for a brown recluse because males are brown with long legs, but it is harmless. For a photo checklist of features that mark a dangerous spider, use the Spider Identifier.

The University of California recommends simple steps rather than sprays, which rarely give lasting control:

• Seal cracks, gaps around pipes and spaces under doors.
• Repair window and vent screens.
• Vacuum webs, egg sacs and spiders from corners, basements and storage areas.
• Reduce clutter and store items in sealed plastic tubs.
• Turn off or dim outdoor lights near doors, since they draw insects that spiders eat.
• Move woodpiles, leaf litter and dense plants away from the walls.