Southern House Spider
Kukulcania hibernalis
Filistatidae (Crevice Weavers), Order Araneae
Physical Description
Large, velvety spider with a significant difference between sexes. Females (like the one pictured) have a bulbous, charcoal to dark brown, teardrop-shaped abdomen and a stocky cephalothorax. They appear quite robust and covered in fine, short hairs.
Size Estimate
Females typically reach a body length of 13-19mm (about 0.75 inches) with a leg span around 2 inches. This specimen appears to be a mature female.
Coloration & Markings
Females are uniform dark brown, charcoal, or lead-gray with no distinct patterns on the abdomen. The cephalothorax is slightly darker. Male specimens are much lighter (amber or tan) and are often mistaken for Brown Recluses.
Web Type
Calamistrate crevice web. They build messy, non-sticky radiating silk lines emerging from a deep retreat or crevice. The silk has a woolly, bluish texture that entangles prey through mechanical snagging.
Eye Arrangement
A tight cluster of eight eyes located on a small, raised tubercle at the front of the cephalothorax. The close grouping is a key diagnostic feature of the Filistatidae family.
Leg Characteristics
The legs are thick and powerful, covered in fine hairs. Males have exceptionally long legs and long pedipalps, whereas females have shorter, sturdier limbs optimized for a sedentary life in crevices.
Venom & Safety Information
Venom Information
Neurotoxic action against insects but extremely weak and harmless to humans. Their venom is not considered medically significant in any way.
Medical Significance
Harmless. Bites are very rare due to their reclusive nature and weak fangs. If a bite occurs, it typically results in localized pain or slight swelling, similar to an ant sting, with no long-term effects.
Safety Recommendations
These spiders are beneficial and safe to have around. If relocation is desired, use a jar to gently scoop the spider and move it to an exterior wall or tree with loose bark.
Habitat & Behavior
Habitat & Range
Common through the Southern United States, from Virginia down to Florida and west to California. They are frequently found on the exterior of homes (stucco, eaves), in barns, and under bridges.
Behavior & Temperament
Very sedentary and shy. Females rarely leave their webs and can live in the same crevice for years. They are not aggressive and typically retreat into their holes when disturbed. They are remarkably long-lived for spiders.
Diet & Prey
Generalist predators eating a variety of crawling insects including beetles, cockroaches, and ants that happen to wander over their radiating trap lines.
Seasonal Activity
Active year-round in warmer climates, though males are most frequently seen wandering in search of females during the late summer and autumn.
Description
The Southern House Spider is a common sight on many homes in the American South. The female is a dark, heavy-set spider that remains hidden in corners or cracks, while the more mobile, light-brown male is frequently seen wandering in search of mates.
Key Features
Velvety texture, teardrop abdomen, dark charcoal/brown coloration, and a small, tight cluster of eyes on a central bump.
Similar Species
Males are often confused with the Brown Recluse (Loxosceles reclusa) but lack the violin mark and have much longer pedipalps. Females may be confused with Wolf Spiders or Lace Weavers but can be distinguished by their eye cluster.
Life Cycle
Females are known for their longevity, often living over 8 years. They produce a white, silken egg sac which they guard inside their retreat. Mating takes place when males follow pheromones to the female’s web.
Ecological Importance
They are exceptional at pest control around human structures, consuming high volumes of cockroaches and beetles that would otherwise enter the home.
Conservation Status
Not evaluated by IUCN; common and stable throughout their range with no known threats.
Interesting Facts
Females can live nearly a decade, which is an unusually long time for a non-tarantula spider. Their silk is produced using a specialized plate called a cribellum, which gives the silk a 'velcro' like quality.
Photography Tips
To identify these, focus on the eye cluster on the front of the head and the texture of the abdomen. Using a flash can help reveal the subtle velvety sheen of the female's body.
Identified: 2026-07-04T19:58:37.753399