Redback Spiders in Australia – What Homeowners Need to Know

Redback spiders are among the most widely recognised – and most feared – spiders in Australia. They’re also among the most common in Australia and surrounding suburbs, which surprises many residents who assume they’re primarily an outback species.

Here’s what Australian homeowners need to know about identifying redbacks, where they’re commonly found, the real risk they pose, and when professional treatment is warranted.

Identifying a Redback Spider

The redback (Latrodectus hasselti) is instantly recognisable once you know what to look for. Key identifying features:

• Size. The female – the dangerous one – has a body approximately 1cm long with a leg span of 2–3cm. Males are significantly smaller (3–4mm body length) and are not considered dangerous.
• Colouring. Females are predominantly black with a distinctive red or orange stripe on the upper abdomen. Some individuals have additional red or white markings on the underside of the abdomen.
• Web structure. Redback webs are irregular and three-dimensional, typically built close to the ground in dark, sheltered locations. The web is noticeably sticky and strong relative to its size – it can trap small lizards and insects.
• Young spiders. Juvenile redbacks are smaller and may show more variable colouring – some have white markings that reduce as they mature. They’re less recognisable but should be treated with the same caution as adults.

If you’re unsure whether a spider is a redback, the Australian Museum’s spider identification resource provides authoritative visual identification guidance.

Where Redbacks Are Commonly Found in Australian Homes

Redback spiders prefer dark, dry, sheltered locations that are protected from rain and direct sunlight. Common locations in Australian homes include:

• Garden sheds and garages. The underside of shelving, behind stored equipment and boxes, in corners near ground level, and inside any hollow or protected structure.
• Under outdoor furniture. The underside of outdoor chairs, tables, pot plant saucers, and garden ornaments are among the most common places Australian residents encounter redbacks.
• Rockeries and garden borders. Under rocks, pavers, railway sleepers, and garden edging – particularly where there’s a sheltered void beneath.
• Letterboxes. A surprisingly common location – the dark, sheltered interior of a letterbox is ideal redback habitat. Check before reaching in.
• Meter boxes and junction boxes. Electrical meter boxes, external junction boxes, and garden irrigation valve covers provide exactly the warm, sheltered environment redbacks seek.
• Under eaves and in downpipe bases. Ground-level downpipe outlets and sheltered spots under eaves with a dark void are frequently occupied.

How Dangerous Are Redback Spiders?

The female redback’s venom is genuinely dangerous and can cause significant illness – but the risk of death is low with modern antivenom treatment. According to the Australian Venom Research Unit, redback bites are the most commonly reported venomous spider bites in Australia, with thousands of bites recorded annually.

Symptoms of a redback bite include:

• Immediate intense pain at the bite site
• Sweating and skin flushing around the bite
• Nausea and abdominal cramping
• Headache
• In severe cases, generalised pain, increased heart rate, and hypertension

If you are bitten by a redback:

• Do not apply a pressure bandage – redback venom spreads through the lymphatic system and pressure bandaging is not appropriate (unlike for funnel-web bites)
• Apply a cold pack to the bite site to reduce pain
• Seek medical attention immediately – redback antivenom is widely available at Australian hospitals and emergency departments
• Keep the affected limb still and below heart level where possible

Bites are most common when people reach into sheltered spaces without checking first – letterboxes, under outdoor furniture, into stored equipment.

When to Call a Pest Controller for Redbacks

Occasional redback sightings in your garden are common in Australia and don’t necessarily indicate an infestation requiring treatment. A single spider relocated with a container is manageable.

Professional treatment is recommended when:

• You’re finding multiple redbacks in and around your home
• You’ve found redbacks in frequently used areas – near play equipment, outdoor entertaining spaces, or areas children access
• You’ve found redbacks inside the home (this is unusual but indicates outdoor population pressure)
• You’ve had a bite incident on your property

A professional spider treatment from Mr Pest Controller applies a residual barrier treatment to all identified redback locations and the property perimeter, significantly reducing spider populations and creating an ongoing deterrent for new spiders entering from surrounding areas.

Treatment is particularly important for families with young children, elderly residents, and properties with significant outdoor entertaining areas.

Book a spider inspection and treatment