Giant House Spider
Eratigena duellica (formerly Tegenaria duellica)
Agelenidae (Funnel Weavers), Order Araneae. Characterized by long spinnerets and sheet-like webs.
Physical Description
A large, robust spider with a hairy appearance. The cephalothorax is pear-shaped and the abdomen is oval. They possess noticeably long, hairy legs and prominent spinnerets at the rear of the abdomen.
Size Estimate
The specimen appears to be an adult. Body length typically ranges from 10-18mm for females, with a leg span that can reach up to 75-100mm (3-4 inches).
Coloration & Markings
Generally brownish/earth tones. The cephalothorax features two dark longitudinal stripes. The abdomen has a series of lighter spots or Chevrons on a dark mottled background. Legs are usually solid brown without distinct banding.
Web Type
Builds large, flat, horizontal sheet webs that lead into a funnel-shaped retreat in a corner or crevice. They do not have sticky silk; they rely on speed to catch prey that trips on the sheet.
Eye Arrangement
Eight eyes of similar size arranged in two slightly curved rows of four. This arrangement provides good motion detection for vibrations on their web.
Leg Characteristics
Notably long and thin compared to the body size. The legs are covered in fine sensory hairs (trichobothria) and lack the distinct dark banding found in many other Agelenids.
Venom & Safety Information
Venom Information
Possess a complex venom designed to paralyze insects. It is not considered toxic to humans.
Medical Significance
Harmless. Their fangs rarely penetrate human skin, and a bite typically results in minor localized redness or swelling, similar to a bee sting, requiring no medical intervention.
Safety Recommendations
If found indoors, they can be safely relocated using the 'cup and paper' method. There is no need for chemical control; they are non-aggressive and medically insignificant.
Habitat & Behavior
Habitat & Range
Commonly found throughout Europe and the Pacific Northwest of North America. They prefer dark, undisturbed areas like basements, garages, woodpiles, and behind furniture.
Behavior & Temperament
Highly active at night. They are exceptionally fast runners, once holding the Guinness World Record for spider speed. Generally shy and will flee rather than bite unless cornered or handled roughly.
Diet & Prey
Generalist predators feeding on various household insects, including flies, beetles, moths, and even other spiders like the hobo spider.
Seasonal Activity
Most visible in late summer and autumn (August to October) when males wander into the open, indoor spaces in search of females.
Description
The Giant House Spider is a common sight in temperate homes during late summer and autumn. Despite their intimidating size and speed, they are beneficial house guests that act as efficient pest controllers.
Key Features
Large leg-to-body ratio, distinct hairy appearance, three tarsal claws, and two dark stripes on the cephalothorax. Lack of leg banding distinguishes it from Barn Funnel Weavers.
Similar Species
Eratigena agrestis (Hobo Spider) which is smaller and has different abdominal patterns, and Tegenaria domestica (Barn House Spider) which is smaller and has banded legs.
Life Cycle
Females produce several lens-shaped egg sacs in autumn, which they guard. Spiderlings emerge in spring. They can live for 2-3 years, which is longer than many other temperate spider species.
Ecological Importance
Critical for indoor pest management. They actively hunt and reduce populations of silverfish, flies, and other potential household pests.
Conservation Status
Not evaluated by the IUCN, but populations are stable and widespread due to their success in human-altered environments.
Interesting Facts
Until being surpassed by sun spiders, they were recorded as the fastest spiders on land, clocked at speeds of 1.73 feet per second.
Photography Tips
Focus on the dorsal (top) view to capture the cephalothorax stripes and abdominal pattern. Lateral shots are best for showing the prominent spinnerets.
Identified: 2026-07-08T14:53:45.774022