Common House Spider, American House Spider
Parasteatoda tepidariorum
Theridiidae (Cobweb Spiders), Order Araneae
Physical Description
The spider has a bulbous, globular abdomen that is noticeably larger than its cephalothorax, typical of comb-footed spiders. It has a delicate structure with slender legs and smooth texture.
Size Estimate
Body length ranges from 5 to 8 mm for females, with a leg span of approximately 1.5 to 2.5 cm. This appears to be an adult or sub-adult specimen.
Coloration & Markings
Base coloration varies from yellowish-brown to dark brown or grey. The abdomen often features darker chevron patterns, spots, or a mottled design, sometimes with light whitish or yellowish patches.
Web Type
Builds an irregular, three-dimensional tangle web commonly known as a cobweb, typically constructed in corners of rooms, near ceilings, or dark sheltered areas.
Eye Arrangement
Has eight small eyes arranged in two rows of four, typical for theridiid spiders, situated on the anterior portion of the cephalothorax.
Leg Characteristics
Legs are long, thin, and spindly with faint darker banding. The hind tarsi possess a comb of serrated bristles used for flinging silk over prey.
Venom & Safety Information
Venom Information
Contains mild neurotoxic venom used to subdue small invertebrate prey. It is not considered dangerous to humans or pets.
Medical Significance
Harmless to humans. A bite is rare and typically results in minor, localized pain, slight redness, or swelling that resolves quickly without medical intervention.
Safety Recommendations
No specific safety precautions needed due to harmless nature. If relocation is desired, gently guide the spider into a container using a piece of paper and release it outdoors.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution globally. Found primarily in human dwellings, outbuildings, barns, cellars, and occasionally outdoors in protected crevices or under logs.
Behavior & Temperament
Docile and non-aggressive. It hangs upside down in its web and retreats when disturbed. It rarely bites unless directly trapped or squeezed against skin.
Diet & Prey
Feeds on a wide variety of household and garden insects, including flies, mosquitoes, beetles, ants, and other small spiders caught in its web.
Seasonal Activity
Active year-round indoors in climate-controlled buildings, with increased movement and mating activity during warmer spring and summer months.
Description
The Common House Spider is a familiar and harmless roommate in homes around the world. Preferring quiet corners, it patiently tends to its tangled web, catching nuisance insects like flies and mosquitoes, making it a welcome natural pest controller indoors.
Key Features
Globular abdomen with chevron markings, tangled cobweb structure, and long spindly legs with a comb-like structure on the hind feet.
Similar Species
Steatoda grossa (False Black Widow) and Latrodectus species (Black Widows). Distinguished by less glossy, patterned abdomens and lack of bright red hourglass markings.
Life Cycle
Females produce brownish, pear-shaped silk egg sacs containing hundreds of eggs. Spiderlings disperse via ballooning after hatching. Lifespan can be up to a year or more for adult females.
Ecological Importance
Acts as an effective natural pest control agent inside buildings by consuming significant numbers of flying and crawling insect pests.
Conservation Status
Not evaluated by the IUCN, but populations are extremely abundant, stable, and widespread globally.
Interesting Facts
These spiders can survive long periods without food and water. Females will often remain in the same web location for their entire adult lives if undisturbed.
Photography Tips
Use macro settings with adequate lighting. Photograph from the side or slightly above to capture the abdominal pattern and web structure clearly while maintaining a safe focus distance.
Identified: 2026-08-14T18:40:33.559688