Giant House Spider
Eratigena duellica (previously Tegenaria gigantea)
Agelenidae (Funnel Weavers), Order Araneae
Physical Description
A large-bodied spider with a pear-shaped cephalothorax and an oval abdomen. It has a slightly hairy texture and long, tapering legs. The cephalothorax features two dark longitudinal stripes on a lighter background.
Size Estimate
Body length 10-18mm; leg span can reach up to 75-100mm (3-4 inches). This appears to be an adult specimen, likely a male based on the leg-to-body ratio.
Coloration & Markings
Typically various shades of brown, tan, and gray. The abdomen often features a mottled pattern with a series of lighter chevrons. The cephalothorax has dark bands, while the legs are usually solid tan or brown without distinct distal banding.
Web Type
Builds a flat, sheet-like funnel web with a tubular retreat at the back. These are often found in dark, undisturbed corners of basements, sheds, or garages.
Eye Arrangement
Eight eyes of similar size arranged in two slightly curved rows of four. This pattern is characteristic of funnel weavers, providing good panoramic vision for detecting movement.
Leg Characteristics
Long, spindly, and hairy (hirsute). They lack the thick spines found on wolf spiders. In males, the legs are proportionally much longer than in females.
Venom & Safety Information
Venom Information
The venom is a mild neurotoxin designed to paralyze small insects. It is not considered toxic to humans.
Medical Significance
Low medical significance. Bites are extremely rare and usually occur only if the spider is squeezed. Symptoms are typically less severe than a bee sting, involving minor localized swelling or redness.
Safety Recommendations
Relocate using the 'cup and paper' method if found indoors. They are harmless and do not require chemical pest control.
Habitat & Behavior
Habitat & Range
Commonly found in the Pacific Northwest of North America and throughout Europe. They prefer dark, damp areas such as basements, crawlspaces, and woodpiles.
Behavior & Temperament
Extremely fast runners but notoriously shy. They are non-aggressive and will typically flee towards their funnel retreat if disturbed. They are active primarily at night.
Diet & Prey
Generalist predators that eat flies, moths, beetles, and even other spiders. They rely on their speed to rush out from their funnel and grab prey that vibrates the web.
Seasonal Activity
Sightings peak in late summer and autumn, particularly in August and September, when males leave their webs to wander in search of mates.
Description
The Giant House Spider is a common sight in temperate homes. Despite its intimidating size and incredible sprinting speed, it is a beneficial roommate that helps manage indoor pest populations.
Key Features
Large leg span, two dark stripes on the cephalothorax, chevron pattern on the abdomen, and lack of distinct bands on the legs.
Similar Species
Often confused with the Hobo Spider (Eratigena agrestis), though the Giant House Spider is larger and lacks the 'serpantine' marking on the sternum. Also confused with Wolf Spiders, which have much larger primary eyes.
Life Cycle
Females produce several lens-shaped egg sacs. Spiderlings emerge and may stay near the mother's web for a short time before dispersing. They can live for 2-3 years.
Ecological Importance
Act as a natural pest control agent in and around human structures, keeping populations of flies and nuisance insects in check.
Conservation Status
Not evaluated by IUCN, but widespread and abundant in urban and suburban environments.
Interesting Facts
At one point, these spiders held the Guinness World Record for the fastest spider, reaching speeds of up to 1.73 feet per second.
Photography Tips
Focus on the dorsal (top) pattern of the cephalothorax and abdomen. Use a fast shutter speed to catch them, as they are prone to sudden bursts of speed.
Identified: 2026-05-08T08:58:28.899327