Giant House Spider, European House Spider
Eratigena atrica
Agelenidae (Funnel-web weavers), Order Araneae. Key family characteristics include the construction of sheet-like webs that end in a tubular retreat, and elongated posterior spinnerets.
Physical Description
The spider has a robust body with an elongated oval abdomen and a distinct cephalothorax. The texture appears moderately hairy, particularly on the legs and mouthparts. This specimen shows prominent palps near the head, indicating an adult male.
Size Estimate
Body length is approximately 12 to 18 millimeters, with a substantial leg span reaching up to 60 to 75 millimeters, typical for an adult male giant house spider.
Coloration & Markings
The coloration consists of earthy tones, featuring shades of brown, dark brown, and greyish-yellow. The cephalothorax has mottled yellowish-brown markings, while the abdomen shows a more mottled or chevron-like pattern.
Web Type
Builds large, flat, non-sticky sheet webs (funnel webs) typically in dark, undisturbed corners, which feature a tubular retreat where the spider waits for prey.
Eye Arrangement
Eight small eyes of roughly equal size arranged in two slightly curved, horizontal rows across the front of the cephalothorax, typical of funnel-web weavers.
Leg Characteristics
Long, robust legs covered in noticeable spines and hairs. The legs are typically spread out widely in a sprawling posture, characteristic of active wanderers.
Venom & Safety Information
Venom Information
Neurotoxic venom used primarily to immobilize insect prey. It is low in potency relative to humans and cannot cause systemic harm.
Medical Significance
Not medically significant. Bites are extremely rare, usually occurring only when the spider is trapped directly against human skin. Symptoms are typically mild and localized, akin to a minor bee sting.
Safety Recommendations
Avoid handling them bare-handed to prevent accidental defensive bites. If relocation is necessary, use a glass and a piece of card to safely carry them outside.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to parts of North America (especially the Pacific Northwest). Prefers damp, cool environments such as cellars, basements, sheds, and dark corners of houses, as well as natural cavities outdoors.
Behavior & Temperament
Fast-moving, nocturnal hunters. They are generally non-aggressive toward humans and will attempt to flee rather than bite, though mature males wander actively in search of mates during late summer and autumn.
Diet & Prey
Feeds on a wide variety of household and garden insects, including flies, silverfish, cockroaches, and other spiders, subduing them with venom after they become trapped on the sheet web.
Seasonal Activity
Most commonly seen in late summer and autumn (specifically September and October) when mature males actively leave their webs to search for females.
Description
The giant house spider is one of the largest spiders commonly encountered indoors. Known for their incredible running speed and sprawling legs, they patrol dark corners and basements, playing a beneficial role in natural pest control while keeping largely out of sight.
Key Features
Large size, long hairy legs, mottled brown coloration, and the presence of a sheet-like funnel web in hidden indoor locations.
Similar Species
Can be confused with other funnel-web spiders such as Eratigena duress and Tegenaria domestica, or potentially wolf spiders, though differing web structures and minute anatomical details distinguish them.
Life Cycle
Females produce disc-shaped egg sacs in late autumn, guarding them until they hatch. Spiderlings disperse in spring, molting several times over two to three years to reach maturity, with a total lifespan of up to several years.
Ecological Importance
Serves as an effective natural predator of common household insect pests, helping to naturally regulate indoor arthropod populations.
Conservation Status
Not evaluated by the IUCN, but populations are secure, widespread, and often expanding due to human habitation.
Interesting Facts
Giant house spiders once held records for running speed among spiders, capable of reaching speeds up to over a foot per second in short bursts.
Photography Tips
Photograph from above against a neutral, contrasting background using natural lighting or a diffused flash to highlight leg spination and body patterns without startling the spider.
Identified: 2026-09-02T21:33:06.257707