# Southern house spider (Kukulcania hibernalis) > A web-building crevice weaver common around buildings in the southern United States; females are dark, chunky and sedentary while males are smaller, slender and wander to find mates. Source: https://insectscanner.com/species/southern-house-spider/ (updated 2026-10-10) ## Is it dangerous? **Mild bite.** Bites are rare and usually cause only minor local pain, redness or swelling. Severe reactions are uncommon but anyone experiencing progressing symptoms, signs of infection, or systemic reaction should seek medical attention. First aid: clean the bite with soap and water, apply a cold pack for comfort, and monitor for allergic response. **Pets:** Generally not dangerous to pets; a bite could cause localized pain or irritation but serious effects are unlikely in dogs and cats. Very small pets might show more noticeable reactions and should be examined by a veterinarian if bitten. ## Quick facts - Scientific name: Kukulcania hibernalis - Order: Araneae (Spiders) - Family: Filistatidae (Crevice weavers) - Size: Females 13-19 mm body length; males about 9-10 mm body length - Colours: Black, Dark brown, Light brown (male) - Habitat: Human structures (eaves, window frames, crawl spaces), rock crevices and under bark in warm temperate to subtropical regions - Range: Southeastern and southern United States, parts of the central U.S., Mexico, Central America and Caribbean islands; associated with human buildings and warm microhabitats - Active: Year-round in warm climates; adult males most commonly seen roaming in late winter to spring when searching for mates, mostly at night and on warm days - Lifespan: Females can live more than 1 year and sometimes several years; males typically live a shorter time and often die after mating - Effect on plants: Pest predator - Pest: no ## Overview Kukulcania hibernalis is a crevice-dwelling spider often found on the exterior and interior of houses in warm regions. Females build messy funnel-like webs near corners, window frames and under eaves and spend most of their lives hiding near the web entrance; males mature into long-legged, wandering spiders that search for females. This species shows strong sexual dimorphism: females remain dark and compact while adult males are smaller, lighter-coloured and sometimes mistaken for different species. They are predators of small insects and other arthropods and are not aggressive toward people. Bites are uncommon and usually produce only minor, short-lived symptoms. Because they capture household pests, many people consider them beneficial despite their off-putting webs. ## How to identify it Females are stocky, velvet-black to dark brown spiders with a stout abdomen and short legs; body length typically 13-19 mm. Adult males are much more slender, with longer legs, a narrower abdomen and a lighter brown to gray pattern; males are typically about 9-10 mm body length but have much longer legs. Juveniles are often mottled and can appear intermediate in colour. The webs are woolly, irregular sheets that radiate outward from a small hole or crack, where the female waits in her retreat. - Strong sexual dimorphism: chunky, dark, sedentary female with a woolly web radiating from a crevice; slender, long-legged, tan male that wanders. - Females 13-19 mm body length and velvet-black to dark brown; males about 9-10 mm, tan to light brown with very long legs. - Webs are irregular, woolly sheets radiating from a hole or crack, often in corners, window frames or under eaves. - Found in cracks, window frames, behind shutters and other narrow crevices on buildings. ## Lookalikes - **Common house spider** (Parasteatoda tepidariorum): Parasteatoda builds rounder tangled orb-like webs and both sexes are similar in appearance; K. hibernalis females are darker and build funnel/retreat webs in crevices. - **Brown recluse** (Loxosceles reclusa): Tan male southern house spiders are often mistaken for brown recluses. Recluses have six eyes in three pairs and a dark violin-shaped mark on the carapace; K. hibernalis males have eight eyes clustered on a small mound, no violin mark, and long, slender pedipalps. ## Life cycle - **Egg sac:** Females produce egg sacs within their web retreat. Each sac contains multiple eggs and is guarded by the female. - **Spiderling (juvenile):** Young spiders hatch from the egg sac and disperse as small spiderlings; juveniles moult several times before reaching adulthood. - **Adult spider:** Adults reach maturity after multiple moults. Females typically remain in or near their web; males roam to find mates and die soon after mating. ## Diet and predators - Young eat: Small flying and crawling insects, other tiny arthropods captured in the web - Adults eat: Insects and other small arthropods that become trapped in the web - Predators of the young: Ants, larger spiders, parasitoid wasps and small insectivorous birds - Predators of adults: Household predators such as larger spiders, some wasps and birds; small mammals may also consume them ## Effect on plants and gardens Does not feed on plants; helps reduce household insect pests such as flies, moths and other small arthropods. ## Where and when to find it Look for female webs in corners, under eaves, behind shutters, window frames, and in cracks on exterior walls; males often wander on walls, fences and building exteriors. - Best time: Late winter to spring is best for seeing roaming males; females and webs are visible year-round in warm areas. Night or dusk may reveal more activity. - Tips: Photograph the web and the spider from several angles to capture male vs female traits. For safety, observe without touching; use a flashlight for night observations. ## Fun facts - Females often remain in or near one web for long periods and can survive for months in the same retreat. - Males are frequently seen wandering along walls and fences in search of mates, especially in late winter and spring. - Adult males are tan with long legs and are often mistaken for brown recluse spiders. ## Frequently asked questions ### Do southern house spiders bite? They can bite if handled roughly, but bites are uncommon and typically cause only mild, temporary pain and redness. ### Are southern house spiders dangerous? Only mildly. They are not considered medically dangerous. Serious reactions are rare; treat bites like minor wounds and seek care if symptoms worsen. ### Why is there a southern house spider in my house? They are attracted to sheltered crevices and buildings because these provide prey and protected sites for their webs. Warm, cluttered areas and cracks in walls are common spots. ### How do I get rid of southern house spiders? Remove webs and egg sacs with a vacuum or broom, seal cracks and gaps where they hide, reduce clutter, and turn off exterior lights that attract prey. Chemical control is rarely necessary; professional pest control can be used for heavy infestations. ### Will they come inside in winter? In warm climates they may be present year-round. Individuals may move into sheltered areas of buildings to avoid cold, but they are not strictly seasonal in mild regions. --- More about this species: [iNaturalist](https://www.inaturalist.org/taxa/122357), [Wikipedia](https://en.wikipedia.org/wiki/Southern_house_spider). Identify insects and spiders from a photo with the Insect Scanner iPhone app: https://apps.apple.com/app/id1543946563?pt=126685406&ct=web-markdown&mt=8 Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.