Identifying the Most Common Spiders in Sydney

Black House Spider

Scientific name: Badumna insignis
Danger Rating: 1/5

Black house spiders, also known as window spiders, can be found across south-eastern Australia. They’re mostly dark brown or black in colour, though their abdomen can be dark grey with faint white markings. They range in size from 9 to 18 mm, with females being about twice the size of males.

These spiders like to make their homes in the crevices of tree trunks and rocks, but will also move into window frames, gutters, and cracks in walls. Their webs are somewhat funnel-like in appearance, but don’t mistake them for funnel-web spiders. Black house spiders don’t burrow in the ground or disguise their webs with debris.

While black house spiders are technically venomous, they are not deadly or aggressive. Their bite will leave you feeling uncomfortable, though, and you may end up with nausea, swelling, and pain in the bite for around 24 hours. If the pain persists or you start to notice any blistering at the wound site, seek medical treatment.

Huntsman Spider

Scientific name: Family Sparassidae
Danger Rating: 2/5

The common huntsman spider is actually a group of over 100 similar spiders in the Sparassidae family. With hairy bodies and legs that span up to 16 cm, they cut an imposing figure, but rest assured they are not as dangerous as they look.

Aside from their size, you can identify huntsman spiders by their elongated front legs, flattened body shape, brown, white, and black markings, and crab-like walk. They prefer to live in small cracks between rocks or underneath tree bark, coming out at night to hunt. They’re notorious for hiding in small, dark places in your house or car and giving you quite a shock when you move the object they were behind.

If you’re bitten by a huntsman spider, don’t panic. Their bites can be quite painful but aren’t toxic.

Garden Orb-Weaving Spider

Scientific name: Eriophora sp.
Danger Rating: 2/5

Like huntsman spiders, garden orb-weaving spiders are a genus that contains around 100 different species. These little spiders like to hang out on leaves during the day, and as such, often have reddish-brown or grey leaf-like markings on their abdomen to blend in.

You can identify garden orb spiders by the two characteristic humps near the front of their triangular abdomen. They range in size from 1.5 to 3 cm, with females being larger than males. Even if you don’t spot the spider itself, you might recognise its delicate, orb-shaped webs strung between shrubs or tree branches.

These spiders aren’t aggressive and prefer to stay outdoors for the most part. If you are bitten by one in your home, though, there’s no need to worry. You might experience some pain, numbness, and swelling for a while, but it will go away on its own.

White-Tail Spider

Scientific name: Lampona cylindrata and Lampona murina
Danger Rating: 3/5

White-tailed spiders are elongated in appearance. They have a reddish-grey abdomen with two pairs of light-coloured spots and a characteristic white marking on the back tip. They’re 12 to 18 mm in size and aren’t picky about where they live, settling just as readily outdoors as in built-up areas.

These spiders aren’t aggressive to humans; in fact, having one or two around may be beneficial as they prey on other spiders. If you want to avoid a bite, shake out any blankets or clothing when you pick them up, as they often hide between folds of fabric.

For years, the white-tailed spider has been associated with dangerous skin ulcers and tissue necrosis. However, research shows that this association is likely false. While their bites are very painful and often react like a bee sting, they don’t cause tissue destruction and aren’t fatal.

Redback Spider

Scientific name: Latrodectus hasselti
Danger Rating: 4/5

These relatives of the famed black widow spider are easily identifiable by the bright red dorsal stripe across a dark brown or black abdomen. They measure between 5 and 15 mm and have long, spindly legs, a small head, and a large, rounded abdomen. Males may be a lighter colour and have less distinct markings than females.

Because redbacks prefer dark, sheltered spots, they are often found living close to people. You’re most likely to stumble across one in your shed or landscaping.

Redbacks will eat not only insects but skinks, small frogs, and baby mice as well. Their triangular webs are sticky enough to trap even large prey.

If a redback bites you, seek medical help. Their bites cause intense pain, nausea and vomiting, weakness, and sometimes convulsions. They aren’t often fatal to healthy adults, but children, pregnant women, and the elderly are at risk.

Funnel-Web Spider

Scientific name: Atrax robustus
Danger Rating: 5/5

Despite their modest size of 25 to 35 mm, funnel-web spiders are the most dangerous on this list. They have shiny, dark brown to black colouration, hairy legs, and prominent spinnerets.

Funnel-web spiders burrow in the ground and spin tube-shaped webs to trap their prey. These webs are often disguised with plant detritus and are hard to see at first glance. They make their homes in dark, damp locations, so keep an eye out for them in gardens and around pools.

Funnel-web spiders are aggressive and will show off their fangs if they feel threatened. Their bites can be fatal to humans, so if you find them in or around your home, do not try to handle them yourself. Leave the area and call a pest removal service right away.

If a funnel-web spider bites you, get medical help immediately.