Wall Spider Identification Australia: Oecobius navus

About the Wall spider / baseboard spider

Wall spider and baseboard spider are common names for Oecobius navus, one of Australia’s minute flat-mesh weavers. Adults remain only about 2–4 mm long, so a pinhead-sized spider is not necessarily a spiderling. The strongest everyday identification combines that scale with a broad flattened body, thin banded legs and a roughly circular or star-like web lying flat against a wall or other hard surface. The web often looks like a dusty patch and has openings around its edge. Colour and indoor location alone are weak evidence, and an ordinary photograph may support Oecobius without proving the species.

How to identify a wall spider or baseboard spider

Scale comes first: Oecobius navus is usually only 2–4 mm in body length, even when mature. From above, the carapace is wider than long with a small projecting front edge, while the abdomen is low and rounded to oval. The thin legs spread around the body and commonly show dark rings. The eyes sit in a tight group nearer the centre of the carapace than the front edge; several are narrow and inconspicuous, so eye detail needs a macro photograph. The family’s expert-level character is a large two-jointed anal tubercle above the spinnerets, fringed with curved bristles, but this should not be sought on a live spider. In the field, combine size and body form with the web: a flat circular or star-shaped shelter about 3 cm across, built closely against the surface with small lateral exits and projecting signal threads. A tiny pale spider without that context remains uncertain.

Clues that are not enough on their own

• Being tiny on a wall, because spiderlings and many adult micro-spiders share that setting
• Pale grey, cream or brown colour without a clear scale and dorsal body view
• A dusty mark or silk patch without visible edge openings, signal threads or the occupant
• Fast running alone, which is also common in juvenile huntsmans, jumping spiders and other wall hunters

Colour, sex and life-stage variation

Colour ranges from nearly translucent cream through pale grey, tan and mottled brown, and darker rings on the legs may fade in poor light. Juveniles are smaller versions of the same general form; mature males may have enlarged pedipalps and wander beyond a web. Fauna Portal currently lists Oecobius as the only Australian oecobiid genus and recognises two Australian species, O. navus and O. putus, so a normal household photograph should not claim O. navus solely from size or colour. The older name Oecobius annulipes appears in Australian literature, but the AFD treats that usage as a misidentification. The hero photograph is an exact-species O. navus web from Gauteng, South Africa. It demonstrates the star-like shelter and hidden spider, but is not proof of an Australian locality or universal colour pattern.

Behaviour, web and retreat

The web is a compact retreat and vibration detector rather than a suspended prey-catching net. Research describes two closely spaced sheets with signal threads extending into the surrounding surface. The spider rests beneath the web with its legs touching the threads, then runs rapidly out when small prey contacts one. It can circle the prey while applying silk before biting and carrying the meal back beneath the sheet; remains may accumulate near the web. Peer-reviewed feeding research found that O. navus is a generalist whose locally common prey can differ: flies and springtails dominated around one studied population, while ants were more important in another. An ant near a wall web is therefore useful context, not a species-defining diet. Sudden wheel-like dashes are normal escape or hunting behaviour, not evidence of danger to people.

Australian distribution

Oecobius navus is a cosmopolitan species associated strongly with buildings and other hard surfaces. The current Australian Faunal Directory explicitly lists records for the Australian Capital Territory, New South Wales, Queensland and Western Australia. It warns that converted regional maps may contain errors and may not show the entire distribution, so the state filters are a documented starting point rather than proof of absence elsewhere. Atlas of Living Australia records confirm Australian collections and observations, but a report from another state should still include scale, the web and a macro photograph.

What to do if you find one

Leave the web in place when practical. Wall spiders are tiny predators of household arthropods, and their flat shelters occupy little space. For identification, photograph the surface at an angle so side lighting reveals the two-layer web, edge openings and signal threads; then use macro mode for the spider without touching it. Do not spray, probe or pluck the web to trigger a dash. If removal is wanted, wipe the small web away only after the spider has moved, or guide a wandering individual into a small clear container with paper. After a suspected bite, follow current Australian health advice and respond to symptoms rather than assuming a tiny spider seen nearby was responsible.

Compare with similar spiders

Use body shape, web or retreat, location and behaviour together before settling on a likely match.

• Black house spider — Black house spider - builds a much larger fuzzy lace web with a distinct funnel-like retreat. The spider is heavier-bodied and larger; shared wall habitat does not make a dusty web Oecobius.
• Tube-dwelling spider — Tube-dwelling spider - occupies a circular silk tube in a crack or hole with lines radiating away from the entrance. A wall spider instead shelters beneath a flat disc-like or star-shaped sheet pressed to the surface.
• Huntsman spider — Huntsman spider - a juvenile may be flat and fast on a wall, but it grows far larger, has the broad sideways huntsman leg stance and does not maintain a tiny flat star web.
• Jumping spider — Jumping spider - can be minute and active on walls, but has two dominant front-facing eyes, moves in stop-start jumps and hunts without the characteristic Oecobius flat web.

Sources for this profile

These accessible authoritative sources support the identification and bite-safety context on this page.

• Australian Faunal Directory: Oecobius navus
• Atlas of Living Australia: Oecobius navus
• Fauna Portal: Australian Oecobiidae
• PubMed: Oecobius navus feeding ecology
• healthdirect: Spider bites

Profile review

Published by Spider Identifier Australia. Last factual review: 10 August 2026.