Grey House Spider, Brown House Spider
Badumna longinqua
Desidae (Intertidal and House Spiders), Order Araneae
Physical Description
The spider has a robust build with a dark, velvety or slightly hairy appearance. The prosoma (cephalothorax) is dark brown to black, compact, and slightly elongated. The opisthosoma (abdomen) is plump, oval-shaped, dark greyish-black, sometimes displaying a subtle mottled or longitudinal pattern depending on the exact morph, though it often appears entirely dark and velvety in darker variants. The overall texture is robust and sturdy.
Size Estimate
Body length is approximately 15 to 18 millimeters, with a leg span reaching around 30 to 40 millimeters. This specimen appears to be a mature adult.
Coloration & Markings
Uniformly dark coloration ranging from dark brown to deep charcoal black. The legs and cephalothorax are dark brown, while the abdomen is charcoal grey to black, sometimes with indistinct, faint lighter mottling along the dorsal midline which can be obscured in very dark individuals.
Web Type
Builds a characteristic messy, funnel-shaped sheet web with a tubular retreat. The web is typically constructed in corners of window frames, under eaves, in bark crevices, or on rough wooden surfaces like the flooring shown in the image.
Eye Arrangement
Eight eyes arranged in two rows of four, typical of cribellate spiders. The eyes are relatively small, compact, and spread across the front of the broad cephalothorax.
Leg Characteristics
Legs are robust, moderately long, and covered in fine setae. The front legs are slightly longer, and the legs often adopt a slightly curved, huddled posture when the spider is resting or defensive.
Venom & Safety Information
Venom Information
Possesses mild neurotoxic venom used to subdue insect prey. Envenomation in humans is uncommon due to their retiring nature.
Medical Significance
Not medically significant. A bite may cause minor local pain, slight swelling, and redness at the site, which typically resolves on its own within a few hours. Rare systemic symptoms such as nausea or sweating have been anecdotally reported from severe bites by related species, but serious medical complications are extremely rare.
Safety Recommendations
Avoid direct handling with bare hands. If found inside, gently capture the spider using a container and a stiff piece of paper, then release it outdoors in a safe, sheltered spot.
Habitat & Behavior
Habitat & Range
Originally native to Australia and New Zealand, Badumna longinqua has been widely introduced to parts of North America, South America, Europe, and Africa. Prefers urban environments, building webs on the exterior and interior of human dwellings, fences, tree trunks, and wooden structures.
Behavior & Temperament
Generally shy, nocturnal, and secretive. They retreat into their silken funnel tubes when disturbed. They are not aggressive toward humans, but mature females guarding egg sacs may bite if accidentally trapped or heavily provoked.
Diet & Prey
Carnivorous ambush predator. Feeds on a wide variety of flying and crawling insects including flies, mosquitoes, moths, beetles, and ants that happen to land or crawl onto the messy sheet web.
Seasonal Activity
Active year-round in temperate indoor environments, with peak foraging and visibility during the warmer spring and summer months when insect prey is abundant.
Description
The Grey House Spider is a familiar nocturnal resident of wooden structures, window frames, and crevices around human habitation. Recognized by its robust dark body and messy funnel-shaped webs, it serves as an efficient natural pest controller against household insects.
Key Features
Robust dark body, velvety appearance, distinct preference for building messy funnel webs in corners or on wood, and a plump charcoal-grey to black abdomen.
Similar Species
Badumna candida (Black House Spider, which is typically darker and more robust), and funnel-web spiders of the family Atracidae (though dangerous funnel-webs possess significantly larger size and massive chelicerae, and differ greatly in geographic distribution).
Life Cycle
Females construct silken egg sacs containing numerous eggs, which are hidden within the retreat of the web. Spiderlings hatch and disperse via ballooning or crawling short distances. Molting occurs multiple times as they grow, and adults can live for several years.
Ecological Importance
Acts as an effective predator of household and garden pests, helping to naturally regulate populations of flies, mosquitoes, and other insects around human dwellings.
Conservation Status
Not evaluated by the IUCN, but populations are abundant, widespread, and frequently expanding due to human habitation and global introduction.
Interesting Facts
Despite being native to Australasia, Badumna longinqua has successfully hitchhiked via international commerce to establish thriving populations in coastal regions worldwide, particularly in temperate urban zones.
Photography Tips
Use macro lenses with good side lighting to highlight the texture of the velvety abdomen and sturdy legs. Maintain a safe distance and photograph from a slightly elevated angle to clearly capture the body proportions.
Identified: 2026-10-16T19:39:54.250223