Giant House Spider
Eratigena duellica
Agelenidae (Funnel-Web Spiders), Order Araneae
Physical Description
A large, robust spider with a hairy cephalothorax and an oval-shaped abdomen. They have a somewhat 'shaggy' appearance due to fine hairs (setae) covering the body. The specimen in the image displays the typical leggy, agile build suited for high-speed locomotion.
Size Estimate
Body length 10-18mm; leg span can reach up to 75-100mm (3-4 inches). Substantially larger than the common domestic house spider.
Coloration & Markings
Displaying a dusky brown to grey base color. The abdomen features a pale, central longitudinal band with dark chevrons or lateral spots. The cephalothorax often has two dark, longitudinal stripes. The legs are typically solid brown without distinct banding.
Web Type
Funnel web. It consists of a flat, messy sheet of non-sticky silk leading into a distinct tubular retreat or funnel where the spider hides (visible in the photo).
Eye Arrangement
Eight eyes of similar size arranged in two rows of four, though this requires high magnification to see clearly. This helps them detect vibration and movement rather than clear images.
Leg Characteristics
Long, slender, and hairy. They lack the heavy spines of wolf spiders but are remarkably fast, once holding the Guinness World Record for spider speed.
Venom & Safety Information
Venom Information
Possess a neurotoxic venom designed to paralyze small insects. It is not considered toxic to humans or domestic pets.
Medical Significance
Low medical significance. Bites are extremely rare as they prefer flight over fight. If bitten, symptoms are typically milder than a bee sting, involving minor localized swelling or redness.
Safety Recommendations
If their presence is unwanted, they can be safely relocated using the 'cup and paper' method. They are harmless to humans and do not require chemical control.
Habitat & Behavior
Habitat & Range
Commonly found in the Pacific Northwest of North America and throughout Europe. They prefer dark, undisturbed microhabitats like basements, caves, woodpiles, and corners of outbuildings.
Behavior & Temperament
Extremely fast runners but generally shy and non-aggressive. They prefer to retreat into their funnel at the slightest vibration. They are active hunters within their web sheet but may wander at night.
Diet & Prey
Generalist predators feeding on various insects, including flies, beetles, moths, and even other spiders. They detect prey by vibrations on the silk sheet and rush out to bite and drag it into the funnel.
Seasonal Activity
Active year-round indoors, but most visible in late summer and autumn when males wander in search of females to mate.
Description
A staple of the late summer and autumn months, the Giant House Spider is a formidable-looking but harmless resident of human dwellings. It is easily identified by its impressive leg span and the characteristic funnel-shaped silk retreats it constructs in dark corners.
Key Features
Large size, distinctive funnel-shaped web, fast movement, and the chevron-like markings on a dark brown abdomen.
Similar Species
Eratigena agrestis (Hobo Spider) - which is smaller and lacks the distinct dark spots on the sternum. Tegenaria domestica (Common House Spider) - which is significantly smaller with banded legs.
Life Cycle
Females produce several pale, spherical egg sacs. Spiderlings emerge and may stay near the mother's web for a short time. They can live for 2-3 years, which is longer than many other common house spiders.
Ecological Importance
Crucial for indoor and perimeter pest control. They provide a significant service by consuming nuisance insects and keeping other spider populations regulated.
Conservation Status
Not evaluated by IUCN, but considered common and stable throughout their range.
Interesting Facts
Until 2010, they held the world record for the fastest land speed for a spider, clocked at 1.73 ft/s. They are also known to be the primary predators of hobo spiders, often keeping hobo populations in check within homes.
Photography Tips
Focus on the dorsal (top) pattern of the abdomen and the structure of the funnel web. Use a flash to highlight the fine hairs and the depth of the retreat tunnel.
Identified: 2026-06-27T02:13:08.514622