Common House Spider at a Glance
Parasteatoda tepidariorum
Also called: American house spider, house spider, cobweb spider, comb-footed spider
Small brown cobweb spider with a round, mottled abdomen that builds messy tangled webs in corners and basements.
- SizeFemales about 4 to 6 mm in body length, males smaller
- ColorTan to brown with darker gray and brown mottling on the abdomen
- BodyEight legs with banded joints, round high abdomen, small head region
- FoundUpper corners, basements, garages, window frames, under furniture
- SeasonIndoors all year, most noticeable from late summer into fall
- DietFlies, ants, mosquitoes, moths, and other small insects caught in the web
The common house spider is the small brown spider behind most of the cobwebs you sweep out of corners. It lives its whole life indoors or right around the outside of the house, and it is the spider Northern Virginia homeowners see more than any other.
It is harmless for practical purposes. A big buildup of webs usually means two things: the house has plenty of small insects to eat, and nobody has disturbed those corners in a while.
How to Identify a Common House Spider
- The body is small, about the size of a pencil eraser or less, with legs that look thin compared to the abdomen.
- The abdomen is round and tall, almost like a ball, and sits high above the legs.
- Color runs from tan to dusty brown with a blotchy pattern of darker gray, brown, and sometimes faint white spots.
- The legs are pale yellow to tan with darker rings at the joints, which gives them a banded look.
- It hangs upside down in a loose, tangled web with no clear spiral or pattern.
- Tan, pear-shaped egg sacs about the size of a pea are often hung inside the web near the spider.
- Webs collect dust fast, so old ones look gray and stringy in corners, behind doors, and along ceiling lines.
Commonly Confused With
Where You Find Them in Northern Virginia
In Northern Virginia homes, house spiders settle where insects travel and people rarely clean: upper corners of rooms, basement ceilings, window wells, garages, crawl spaces, and the gaps behind appliances. Outside, they web under eaves, porch ceilings, deck rails, and around exterior lights that pull in moths at night. Because indoor temperatures stay steady, they stay active all year inside, though most homeowners notice them more from late summer into fall when adult numbers peak.
Life Cycle and Behavior
A female can produce several egg sacs over her life, and each sac can hold a few hundred eggs. Spiderlings hatch inside the sac, crawl out, and often stay in the mother's web for a short time before spreading out on silk lines to find their own corner. They molt several times as they grow, and an adult can live a year or more indoors. Since one female can make many sacs, a quiet basement can go from a few webs to dozens without anyone seeing the spiders arrive.
Health and Property Risks
Common house spiders are not considered a health threat. They are timid, and bites are rare and usually happen only when one is pressed against skin. A bite, if it happens, is typically mild, similar to a small insect sting. Anyone with an unusual reaction, spreading redness, or a wound that worsens should contact a doctor. The real problem is the mess. Webs stain ceilings, trap dust, and make a finished basement or garage look neglected, and heavy webbing is often a sign of a larger insect problem feeding the spiders.
Signs of Activity
- Tangled, irregular cobwebs in corners, under shelves, and along ceiling edges
- Small tan egg sacs hanging inside webs
- Dead insects and insect parts caught in webs or dropped on the floor below
- Webs that return within days of being cleaned
- Spiders clustered around windows and exterior lights where insects gather
Prevention Tips
- Vacuum webs, spiders, and egg sacs regularly, then empty the vacuum outside so sacs do not hatch indoors.
- Swap white exterior bulbs for yellow or warm LED bulbs, which attract fewer of the insects spiders feed on.
- Seal gaps around windows, doors, utility lines, and dryer vents with caulk or weatherstripping.
- Run a dehumidifier in basements and crawl spaces to cut down on moisture-loving insects.
- Store items in sealed plastic bins instead of cardboard boxes, which give spiders hiding spots.
- Keep firewood, mulch piles, and dense shrubs a few feet away from the foundation.
Professional Common House Spider Control
When we visit, we start by walking the inside and outside of the home to see where webs are concentrated and what insects are feeding the spiders. We confirm the species, because a few brown cobweb spiders call for a different plan than a widow or a heavy insect issue. From there, our spider control service pairs web removal at eaves and entry points with targeted treatment along the foundation, window frames, and other harborage areas. We point out gaps worth sealing and check back on follow-up visits so the corners stay clear.
Common House Spider FAQs
House spiders have venom, like nearly all spiders, but it is weak and not a known risk to people. They rarely bite, and when they do, it is usually because one got trapped against skin. Most bites cause mild redness and itching that fades on its own. If a bite looks infected, keeps spreading, or causes symptoms beyond the spot itself, contact a doctor.
Spiders go where the food is. A lot of house spiders usually means a steady supply of small insects such as flies, gnats, and moths, often drawn in by moisture or outdoor lights. Cluttered basements and garages also give them quiet places to web. Cutting the insect supply and sealing entry points does more to reduce spiders than knocking down webs alone.
A few house spiders in a garage or basement do little harm and eat insects you do not want. Problems start when webs build up in living spaces or the numbers keep climbing. Vacuuming is the easiest way to remove spiders and egg sacs. If webs keep returning, the underlying insect problem or entry points are worth having inspected.
An adult common house spider can live a year or more indoors, where steady temperatures protect it from winter. During that time a female may lay several egg sacs, each holding a few hundred eggs. That is why a lightly used room can fill with webs faster than people expect, and why removing egg sacs matters as much as removing spiders.
