Giant House Spider
Eratigena duellica
Agelenidae (Funnel-Weavers), Order Araneae
Physical Description
A large, hairy spider with a relatively small cephalothorax compared to its long, robust legs. The abdomen is egg-shaped and features distinct spinnerets. It has a mottled appearance with stiff hairs (setae) covering the body and legs, giving it a somewhat rugged texture.
Size Estimate
Body length 10-18mm for females; leg span can reach up to 10cm (4 inches) in adult males.
Coloration & Markings
Displaying earthy tones of brown, tan, and grey. The cephalothorax features two dark longitudinal stripes. The abdomen has a series of lighter 'chevrons' or spots patterns. The legs are typically solid brown without distinct banding.
Web Type
Funnel web: A flat, sheet-like web that narrows into a silk tube or funnel where the spider hides. Usually built in corners, crevices, or under debris.
Eye Arrangement
Eight eyes in two nearly straight rows of four. They are small and adapted for detecting movement and light levels rather than high-resolution vision.
Leg Characteristics
Notably long and hairy. They lack the thick spines seen in wolf spiders but are very fast. In males, the legs are significantly longer in proportion to the body.
Venom & Safety Information
Venom Information
Possesses venom used to subdue insects; it is not considered toxic to humans. It is primarily protein-based and lacks the neurotoxins or cytotoxins found in medically significant species.
Medical Significance
Low medical significance. Bites are rare because the spider's fangs are small and it prefers flight over fight. A bite may cause minor redness or localized itching, similar to a bee sting.
Safety Recommendations
Relocate using the 'cup and paper' method if found indoors. Seal cracks and gaps around doors/windows to prevent entry if their presence is unwanted. No medical treatment is usually required for bites beyond cleaning the area.
Habitat & Behavior
Habitat & Range
Commonly found in the Pacific Northwest of North America and throughout Europe. Prefers dark, undisturbed areas like basements, garages, woodpiles, and crawl spaces.
Behavior & Temperament
Extremely fast runners but generally shy and non-aggressive. They prefer to retreat into their funnel webs or dark corners when disturbed rather than confront a threat.
Diet & Prey
Generalist predator feeding on house flies, moths, beetles, and even other spiders. They detect vibrations on their sheet web to rush out and grab prey.
Seasonal Activity
Active year-round indoors, but most visible in late summer and autumn when males wander in search of mates.
Description
The Giant House Spider is an impressive arachnid known for its size and incredible speed. Often mistaken for more dangerous species due to its hairy legs and large gait, it is actually a beneficial roommate that provides excellent natural pest control.
Key Features
Large size, long hairy legs without bands, two dark stripes on the cephalothorax, and the characteristic funnel-web architecture.
Similar Species
Often confused with the Hobo Spider (Eratigena agrestis), which is smaller, or Wolf Spiders (Lycosidae), which have a different eye arrangement and do not build funnel webs.
Life Cycle
Females produce several white, silk egg sacs. Spiderlings emerge and may stay in the mother's web for a short time before dispersing. Common lifespan is 2-3 years.
Ecological Importance
Critical for indoor and perimeter pest control, keeping populations of flies, silverfish, and moths in check.
Conservation Status
Not evaluated by IUCN, but populations are stable and common in urban/suburban environments.
Interesting Facts
Until recently, it held the Guinness World Record for the fastest spider speed (approx. 1.73 ft/sec) before being surpassed by sun spiders. They are also known to eat Hobo spiders.
Photography Tips
Focus on the cephalothorax patterns and the spinnerets at the rear. Use a macro lens to capture the hair texture. High shutter speed is needed if the spider is active due to its extreme velocity.
Identified: 2026-06-15T04:58:24.981824