Southern House (Kukulcania hibernalis)
The southern house spider is the maker of those grey, dusty starbursts of silk that fan out from cracks in stucco walls, porch columns and window frames across the southern United States. Females are big, velvety and almost never seen outside their crevice; the tan, long-legged males wander in the open and are the single most common spider mistaken for a brown recluse.
By Dr. James WatuwaPublished January 17, 2019Updated September 13, 2026✓ Reviewed by Dr Richard J. Pearce (PhD)
In this guide
Physical description and identification
Two animals that look nothing alike carry this one name, and that is the whole difficulty of identifying Kukulcania hibernalis. The female is a heavy, sooty, velvet-covered spider that almost never leaves her crack in the wall; the male is slim, sandy-tan and leggy. Householders meet the male and the web, and very rarely the female.
Adults
- Size: females measure 13–19 mm (about 0.5–0.75 in) in the body with a leg span approaching 5 cm, making them one of the larger spiders on southern houses. Males are 9–10 mm but look bigger because of their long, thin legs.
- Color: sexual dimorphism is unusually strong. Females are charcoal grey to brown-black under a coat of short pale hairs that gives a soft, matt finish, with darker mottled patches on the carapace. Males are uniformly light brown, amber or tan, with no pattern on the abdomen.
- Eyes: the single most useful character. All eight eyes are packed onto a small raised tubercle at the front of the head, so at a glance they read as one dark dot rather than rows or pairs. No arrangement of spider eyes in the recluse group looks like this.
- Distinctive features: the female's abdomen is bulbous and becomes visibly distended after a large meal or when she is carrying eggs. The male has strikingly long pedipalps that project forward past the head, ending in the swollen bulbs of maturity. Both sexes are cribellate: a cribellum, a plate of thousands of tiny silk outlets, sits in front of the spinnerets, and each fourth leg carries a calamistrum, a comb of bristles that cards that silk into a woolly ribbon.
Eggs and egg sac
A mature female produces a loose, off-white ball of silk roughly 15 mm across holding in the region of 200 eggs. She never hangs it in the open: the sac stays deep inside the silk tube at the back of her crevice, and she replaces it several times over a long adult life.
Spiderlings
Hatchlings are pale and darken with each molt. They stay in the maternal web for several weeks and tolerate one another instead of dispersing or cannibalising at once — a mild sub-social habit that is genuinely unusual among spiders. Popular accounts push this into organised cooperative hunting and sibling recognition, which overstates the evidence: what is documented is tolerance, shared silk and feeding together at one prey item. The tan male colouring appears only at the final molt.
The web
The web identifies the species without the spider being seen. From a hole or crack — a weep hole in brickwork, a split in stucco, a gap behind a shutter — the spider lays a radiating fan of silk spreading 10–20 cm across the surface, backed by a silk-lined tube running into the cavity where she waits. The threads are cribellate: dry, woolly and free of glue, snagging insect bristles and claws in a mesh of nanofibres. Because she adds to the web rather than rebuilding it, an old one is a grey, dust-laden sunburst. For how this differs from the glue-coated spiral of an orb, see our guide to spider webs.
Where the southern house spider lives
Kukulcania hibernalis is the most widely distributed member of its genus and one of the most abundant spiders on buildings in the warm Americas. In the United States it runs along the Gulf and southern Atlantic states — Florida, Georgia, the Carolinas, Alabama, Mississippi, Louisiana and Texas — with inland records north to Tennessee and Arkansas and introduced populations in California, then continues through Mexico and the Caribbean into Central and South America as far as Uruguay, Brazil and northern Argentina. Hard winters set the northern limit.
The habitat requirement is simple, and it is a hole. Natural sites are rock faces, tree hollows and loose bark; around people it takes weep holes, mortar joints, cracked render, gaps behind shutters and downpipes, porch ceilings, sheds, barns and bridges. It colonises the outside of buildings rather than the rooms inside, which is why it lands on lists of southern house spiders while living on the wall. A wall beside an outdoor light carries more retreats than a dark one, because the light delivers the moths.
Are southern house spiders venomous?
Yes, in the ordinary sense that nearly all spiders are venomous: Kukulcania hibernalis has venom glands and uses them on flies, moths and beetles. It is not venomous in the sense that worries people. The venom has no known medical significance for humans or pets, no antivenom exists because none has been needed, and no verified case of tissue damage or systemic illness is attributed to this species. It is not related to the recluse spiders and lacks sphingomyelinase D, the enzyme behind the skin lesions of a genuine brown recluse bite. Confusing the two is a naming problem, not a medical one.
Can southern house spiders bite?
They can, and they hardly ever do. The female's entire defence is to vanish backwards into her tube. Males do not defend themselves either; one scooped into a cupped hand runs rather than bites. Older accounts call the males the aggressive sex — they are simply the sex you see moving, and movement gets read as aggression.
The few documented bites involve a spider pressed against skin: a hand sliding into a gap in a wall, or a wandering male trapped in a sleeve. The result is a brief pinch and a small red mark, sometimes with mild itching, settling within a day or two after washing the site and applying a cold pack. There is no necrosis and no systemic reaction. If a wound spreads, ulcerates or comes with fever, see a doctor — not because of this spider, but because those signs point to a bacterial infection, the usual real cause of sores blamed on spiders.
Southern house spider or brown recluse? Count the eyes and look at the palps. A male southern house spider has eight eyes crowded onto one small raised bump, very long forward-pointing pedipalps with swollen tips, and a plain tan abdomen. A brown recluse has six eyes in three well-separated pairs, short palps, and a dark violin mark on the carapace with its neck pointing backwards. The house spider is also larger, and it sits beside a fan of grey silk — recluses build a small untidy retreat and never a radiating sheet.
Ecological importance and behavior of the southern house spider
This is a sit-and-wait predator with an extreme commitment to one address. A female may hold the same crevice for her whole adult life, extending the silk fan around it year after year. She rests inside with her front legs on the radiating lines; when a fly, moth, beetle or ant blunders into the threads, the vibration brings her out in a rush and the prey is bitten and hauled back into the tube. With eyes this small and clustered, vision plays almost no part.
Natural predators: birds and lizards such as anoles and geckos take exposed spiders, especially wandering males; mud-dauber wasps paralyse them to stock clay nests; centipedes and larger spiders take any that leave cover. Never fully emerging is much of the reason the female lives so long.
Prey-predator dynamics: a wall carrying a dozen retreats is a standing insect trap set exactly where flying insects concentrate — lights, doorways and eaves.
Seasonal behavior and mating: in the warm south the species is active year-round. Males mature, stop feeding and leave to search, which is why indoor sightings cluster in spring and autumn. Mating is drawn out: the male taps at the edge of the web, is admitted, and the pair can stay coupled and almost motionless for an hour or more. Males die within weeks or months; females keep growing, molting and producing egg sacs for years.
Relationship with humans: harmless and useful. Where the silk fans are unwanted, a brush and a tube of caulk beat insecticide — seal the crevice and the site is no longer habitable.
Similar spiders and how to tell them apart
| Spider | How it differs from the southern house spider |
|---|---|
| Brown recluse (Loxosceles reclusa) | Six eyes in three pairs, violin mark, short palps, smaller and medically significant. No radiating wall web. This is the confusion that matters. |
| Other recluse spiders (Loxosceles) | Same six-eye pattern and the same thin, smooth, spineless legs; desert and rock habitats in the arid Southwest. |
| Arizona black hole spider (Kukulcania arizonica) | Same genus and same web architecture, but smaller and a desert species of Arizona and its neighbours rather than the humid Southeast. |
| Kukulcania geophila | Another close relative, smaller again, tied to ground-level crevices and rock in the Southwest and Mexico. |
| Hacklemesh weaver (Metaltella simoni) | Also cribellate and common in the Gulf states, but 6–9 mm, glossy reddish-black, eight eyes in two rows, mesh web at ground level. |
Quick facts
| Scientific name | Kukulcania hibernalis (Hentz, 1842), family Filistatidae. |
|---|---|
| Distribution | Southern US from Texas to Florida and the Carolinas, plus California; Mexico, the Caribbean, Central America and South America to Uruguay, Brazil and northern Argentina. |
| Habitat | Cracks and holes in masonry, stucco, brick and timber; also rock faces, tree hollows and loose bark. |
| Diet | Flies, mosquitoes, moths, beetles, ants and cockroaches snagged in the cribellate silk. |
| Web | A fan of dry, woolly cribellate lines radiating 10–20 cm from a silk-lined tube in a crevice; added to, never rebuilt. |
| Lifespan | Females several years, reportedly up to about eight; males weeks to months after maturing. |
| Predators | Birds, anoles and geckos, mud-dauber wasps, centipedes and larger spiders. |
| IUCN status | Not evaluated. Common, widespread and in no sense threatened. |
Did you know?
- The species was described as Filistata hibernalis by Nicholas Marcellus Hentz in 1842 and moved to the genus Kukulcania by the Finnish arachnologist Pekka T. Lehtinen in 1967.
- Kukulcania honours Kukulkan, the feathered-serpent deity of the Maya — a male god, not a serpent goddess as is often repeated.
- Filistatidae is an ancient haplogyne lineage: the females lack the hardened external genital plate of most araneomorphs, and the family sits near the base of the araneomorph tree.
- Because females are so sedentary and so long-lived, one silk fan on a garden wall can belong to the same individual for the better part of a decade.
In summary, the southern house spider is a harmless, long-lived crevice specialist whose grey sunburst of silk is a familiar sight on southern walls. Learn the two forms — the bulky velvet female and the tan, long-palped male with eight eyes on a single bump — and the recurring scare about a house full of brown recluses resolves itself in seconds.
Frequently asked questions about the southern house spider
How do you tell a southern house spider from a brown recluse?
Look at the eyes and the size. A southern house spider has eight eyes packed onto one small raised bump, and males have very long forward-pointing pedipalps. A brown recluse has six eyes in three separated pairs and a violin mark on the carapace. The house spider is also larger and lives beside a fan of grey silk on a wall.
What is the difference between male and female southern house spiders?
They look like different species. Females are 13 to 19 mm, bulky, and charcoal to brown-black with a velvety coat of pale grey hairs. Males are 9 to 10 mm, slim, tan or amber, with much longer legs and long swollen-tipped palps. Only males wander in the open; females stay in their crevice.
Is a southern house spider bite dangerous?
No. Bites are rare because the spider retreats rather than defends itself, and the venom has no medical significance for people or pets. A bite feels like a brief pinch and leaves a small red mark that fades within a day or two. Wash the area and use a cold pack; no antivenom exists because none is needed.
What does a southern house spider web look like?
It is a fan of dry, woolly silk lines radiating ten to twenty centimetres out from a hole or crack, with a silk tube running back into the cavity. The threads carry no glue and snag insects by friction. Because the spider adds silk instead of rebuilding, old webs collect dust and look like grey starbursts on a wall.
Are southern house spider spiderlings really social?
Only partly. Hatchlings stay in the mother's web for several weeks and tolerate each other closely, which is unusual among spiders and is a mild form of sub-social behaviour. Claims of organised cooperative hunting and sibling recognition go beyond the evidence; what is documented is tolerance, shared silk and feeding together at one prey item.
How many eggs does a female southern house spider lay?
Roughly 200 eggs at a time, held in a loose ball of silk about 15 mm across. She keeps the sac deep inside her silk tube at the back of the crevice and guards it there, never hanging it in the open. Over a long adult life she produces several sacs.
Where do southern house spiders build their webs?
Almost always on the outside of structures, using any hole that leads into a cavity: weep holes in brick, cracks in stucco, mortar joints, gaps behind shutters and downpipes, porch ceilings, barns and bridges. In natural habitat they use rock crevices, tree hollows and loose bark. Walls beside outdoor lights carry the most retreats.
How long do southern house spiders live?
Females are unusually long-lived for an araneomorph spider, commonly surviving several years and reportedly reaching about eight. They keep growing and producing egg sacs throughout. Males live only weeks to a few months once mature, because they stop feeding and leave the web to search for females.
Where are southern house spiders found?
They occur across the warm Americas: the southern United States from Texas through the Gulf states to Florida and the Carolinas, plus introduced populations in California, then Mexico, the Caribbean, Central America and South America as far as Uruguay, Brazil and northern Argentina. Cold winters set the northern limit.
How do I get rid of southern house spiders on my house?
Brush the silk away and seal the crack behind it with caulk or mortar, because the crevice is the resource the spider needs. Spraying the wall is largely wasted since the spider sits deep inside the cavity. Replacing bright white outdoor lights with warm or motion-activated fittings cuts the insect supply that supports them.
References
- World Spider Catalog (2026). Kukulcania hibernalis (Hentz, 1842). Natural History Museum Bern. wsc.nmbe.ch/spec-data/17013/taxon
