A Redback Spider Bite Won't Kill You (if You Get Antivenom in Time)

The Australian redback spider and North American are both venomous spiders that you want to avoid whenever possible. Jenny Dettrick / Getty Images

The redback spider (Latrodectus hasselti) is one of Australia's most iconic arachnids. It's a member of the widow spider family, closely related to the black widow spider. They're famous for their distinctive red markings and potent venom.

While redback spider bites can cause pain, advances in antivenom treatment have made these encounters much less dangerous. But it's definitely a spider that humans should avoid.

How to Identify the Redback Spider

These are tiny spiders. Female redback spiders are about 0.4 inches (10 mm), while male redback spiders are much smaller, only about 0.11 to 0.16 inches (3 to 4 mm).

Female redback spiders are easy to identify by their shiny black bodies, slender legs and iconic red stripe running down their abdomen. In some cases, this stripe may be broken or absent, but most females sport something similar to the vivid red hourglass you'll find on black widows.

Male spiders are pale brown with faint white markings and lack the bright red stripe. Young spiders resemble males in coloration until they mature. The redback is often mistaken for its cousin, the black widow, but the Southern Hemisphere cousin is smaller.

Are Redback Spiders Dangerous?

Yes, Australian redback spiders are dangerous. Redback spider venom contains neurotoxins that can cause severe pain, sweating and systemic symptoms such as nausea and muscle spasms. Redback bites are more commonly inflicted by a female redback, as the male redback spiders rarely bite humans.

Luckily, antivenom treatment for redback spider bites has been available since the 1950s, significantly reducing the risk of severe complications. Fatalities are now extremely rare. However, bites should always be treated promptly.

Where Are Redback Spiders Commonly Found?

The redback spider is native to Australia but has also become an invasive species in other parts of the world, including New Zealand and parts of Asia.

These spiders are highly adaptable and thrive in urban and rural areas alike. You'll often find them hiding in sheltered locations such as garden sheds, under outdoor furniture or even in mailboxes.

The invasive Australian redback spider prefers dry, warm environments and is skilled at making webs in human-made structures.

What Attracts and Deters Redback Spiders?

Redback spiders are attracted to environments with abundant prey and sheltered areas for web-building. Their diet includes insects and even small vertebrates that get caught in their webs.

The female's web is irregular and sticky, designed to trap prey while providing a hiding spot for the spider. Male redback spiders often venture into the female's web during mating season, making these sites even busier.

To deter redback spiders, keep your yard and home clean and free of clutter where webs might form. Regularly check outdoor furniture, garden tools and storage areas for signs of webs or young spiders. Sealing gaps in walls and doors can also help keep these venomous spiders out of your living spaces.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.