Giant House Spider
Eratigena duellica (formerly Tegenaria gigantea)
Agelenidae (Funnel-Weavers), Order Araneae
Physical Description
A large-bodied spider with a robust cephalothorax and a bulbous, oval-shaped abdomen. The abdomen is typically hairy with a mottled appearance. Females have a larger and more rounded abdomen than males, who possess longer legs and prominent pedipalps.
Size Estimate
Body length 10-18mm; leg span can reach up to 75-100mm (3-4 inches). This specimen appears to be an adult female based on the large abdomen.
Coloration & Markings
Generally shades of brown, tan, and grey. The cephalothorax often features two longitudinal dark stripes. The abdomen has a pattern of pale chevrons or spots on a darker background. The legs are usually solid brown or faintly banded.
Web Type
Messy, flat, horizontal sheet web leading to a tube-shaped funnel retreat in a corner or crevice. Non-sticky silk rely on speed to capture prey.
Eye Arrangement
Eight eyes of similar size arranged in two rows that are slightly curved, typical of the Agelenidae family.
Leg Characteristics
Long, hairy legs with visible spines. The legs are notably hairy (sensilla) which helps them detect vibrations from prey on their sheet webs.
Venom & Safety Information
Venom Information
Possesses a mild neurotoxic venom used to paralyze insect prey. The venom is not considered medically significant to humans.
Medical Significance
Low danger level. Bites are rare and usually only occur if the spider is pressed against skin. Symptoms are typically less severe than a bee sting, involving minor localized swelling or redness.
Safety Recommendations
If found indoors, they can be easily relocated using the 'cup and cardboard' method. Wear gloves when moving woodpiles or cleaning dark corners where they might hide.
Habitat & Behavior
Habitat & Range
Commonly found in the Pacific Northwest of North America and throughout Europe. They prefer dark, undisturbed areas like basements, sheds, garages, and woodpiles.
Behavior & Temperament
Extremely fast runners but generally shy and non-aggressive. They prefer to flee to their funnel retreat when disturbed. They are active hunters that wait at the edge of their funnel for vibrations.
Diet & Prey
Generalist predators feeding on various household insects including flies, moths, beetles, and even other spiders including the Hobo spider.
Seasonal Activity
Most visible in late summer and autumn (August-October) when mature males leave their webs to wander in search of mates.
Description
The Giant House Spider is one of the largest spiders found in domestic settings in temperate regions. Despite their intimidating size and incredible speed, they are beneficial roommates that provide excellent pest control.
Key Features
Large size, long hairy legs, funnel-shaped web, and the 'sternum' marking (usually featuring four pairs of pale spots) which distinguishes them from similar Tegenaria species.
Similar Species
Hobo Spider (Eratigena agrestis) which is smaller with shorter legs; Domestic House Spider (Tegenaria domestica) which is significantly smaller and more common indoors.
Life Cycle
Females produce several white, papery egg sacs throughout autumn. Spiderlings hatch and may stay near the mother's web initially. They can live for 2-3 years, which is long for a temperate spider.
Ecological Importance
Critical urban predators that manage populations of flies and woodlice. In the Pacific Northwest, they are known to outcompete and displace the more 'suspect' Hobo spider.
Conservation Status
Not evaluated by the IUCN, but populations are stable and widespread in human-disturbed habitats.
Interesting Facts
For a long time, these were held in the Guinness World Records as the fastest spiders, capable of reaching speeds of up to 1.7 feet per second.
Photography Tips
A side profile helps show the leg-to-body ratio. To get a clear shot of the markings, use a light source to illuminate the hairs on the abdomen without creating a reflection.
Identified: 2026-07-12T22:48:14.541331