Grey House Spider, Domestic House Spider
Badumna longinqua
Desidae (Intertidal and House Spiders), Order Araneae. Key family characteristics include a cribellum and calamistrum in some genera, though lost in others, and a preference for making dense, tangled sheet webs with a tubular retreat.
Physical Description
The body is robust and compact, featuring a dark brown to charcoal cephalothorax and a distinctly lighter, greyish-brown to pinkish oval abdomen. The surface has a velvety texture due to dense covering of fine setae (hairs).
Size Estimate
Body length typically ranges from 9 to 15 mm for females, with males slightly smaller around 6 to 10 mm. The leg span is approximately 25 to 30 mm. The pictured specimen appears to be an adult or sub-adult.
Coloration & Markings
The cephalothorax is dark brown to blackish, while the abdomen is a dusty grey-brown with mottled, indistinct lighter markings or a faint cardiac mark. The legs exhibit dark banding or a mottled grey appearance.
Web Type
Builds a characteristic messy, sheet-like web that resembles a dense funnel or lace, often constructed in corners, window frames, and crevices. The web features a tubular retreat where the spider hides.
Eye Arrangement
Eight eyes arranged in two slightly curved rows across the broad front of the carapace, typical of cribellate spiders, with eyes of relatively similar size.
Leg Characteristics
Leaning toward robust and moderately long legs with dense hair (setae) and distinct dark and light banding. The legs are held in a typical crouching posture near the body when resting inside the tubular retreat.
Venom & Safety Information
Venom Information
Possesses mild neurotoxic venom used to immobilize insect prey. It is not considered dangerous to humans.
Medical Significance
Low medical significance. A bite may cause localized pain, swelling, and redness, and in rare cases, systemic symptoms like nausea or sweating if an allergic reaction occurs, but severe necrosis or systemic toxicity is exceedingly rare.
Safety Recommendations
Avoid direct handling with bare hands. If found inside, gently guide the spider into a container using a piece of paper and release it outdoors. Seal home entry points to discourage indoor nesting.
Habitat & Behavior
Habitat & Range
Native to Australia, but widely introduced globally including New Zealand, parts of the Americas, and Europe. Prefers human habitations, building exteriors, tree bark, fences, and dark crevices.
Behavior & Temperament
Reclusive and nocturnal, spending most of the day hidden inside its silk retreat. It is non-aggressive towards humans and will typically retreat when disturbed, only biting if firmly trapped or pressed against the skin.
Diet & Prey
Primarily feeds on flying insects such as flies, moths, mosquitoes, and beetles that happen to land or become entangled in the non-sticky cribellate web.
Seasonal Activity
Active year-round in temperate indoor environments, with peak visibility and mating activity occurring during the warmer spring and summer months.
Description
The Grey House Spider is a familiar yet elusive nocturnal arachnid commonly found frequenting our homes, window frames, and garden walls. Sporting a velvety, dark thorax and a dusty grey-brown abdomen, this species constructs messy, characteristic funnel-like web retreats. Though their webs can accumulate dust and appear untidy, these spiders act as efficient biological pest control agents, quietly subduing household pests like flies and moths.
Key Features
Robust, velvety body with a dark cephalothorax contrasted by a dusty grey or pinkish-brown abdomen, combined with the signature messy sheet web featuring a tubular retreat in structural crevices.
Similar Species
Tegenaria species (Funnel-web grass spiders / Giant house spiders), which generally have longer legs, different spinneret arrangements, and build flat sheet webs without a prominent dense tube.
Life Cycle
Females construct silken egg sacs hidden within the retreat or nearby crevices. Spiderlings disperse via ballooning after hatching. They undergo multiple molts to reach maturity and can live for several years.
Ecological Importance
Serves as an effective natural predator of common household and garden insect pests, helping to keep fly and mosquito populations in check around human structures.
Conservation Status
Not evaluated by the IUCN, but highly secure and widespread due to its successful adaptation to human-modified environments and global introduction.
Interesting Facts
Badumna longinqua has successfully hitchhiked across oceans through human commerce, establishing resilient populations in countries far from its native Australian habitat.
Photography Tips
Photograph from a slightly elevated angle with macro settings to capture the texture of the setae on the abdomen and cephalothorax. Ensure soft, diffused lighting to avoid harsh reflections on any metallic surfaces nearby.
Identified: 2026-09-15T12:49:51.222380