Redback Spiders - All you need to know...

Last Updated: December 4, 2025

Gordon Reidy

spider control, Spider information

The redback spider (Latrodectus hasselti) is found across Australia. Being common in urban areas it is one of the most frequent causes of spider bites. Control and prevention is relatively straightforward through a pest control spray treatment.

Female redback spider with classic red markings

Redback spider bite

Redback spider venom

The redback venom is a neurotoxin that works directly on the nerves. An antivenom has been available since 1956, however recent research has shown that the anti-venom has no significant benefit over a placebo.

Redback spider bite symptoms

The redback spider bite is painful and the pain increases rapidly, progressing up the affected limb and lasting at least 24 hours. Other symptoms include sweating (also local sweating at bite location), nausea and vomiting. Abdominal pain, high blood pressure and tachycardia can also occur.

Redback spider bite treatment (first aid)

The patient should sit down and try to relax
Clean the bite with water and disinfectant
Apply an ice pack to the bite area
If possible, collect the spider or take a picture for identification (if medical treatment is required)
If symptoms worsen seek medical attention

DO NOT apply a pressure bandage, as this worsens the pain and does little to stop venom movement (as it is slow moving anyway).

The recommended treatment is to take pain killers. The painkillers should reduce the pain, but are unlikely to eliminate the pain completely. If the pain does not decrease or if the victim exhibits severe symptons (especially in children), seek medical advice.

Medical Disclaimer: While we make every effort to make sure the information in this website is accurate and informative, the information does not take the place of professional or medical advice.

Redback Spider Identification

What do redback spiders look like?

Female redback spider

This is the redback most people are familiar with. Females are a shiny, black spider up to 3cm long, with an obvious red/orange stripe on the upper side of the abdomen and an hourglass mark on the underside of the abdomen. However, there can be colour variations – their colour may vary from black to brownish and sometimes the red stripe can be broken.

A female redback can live for 2-3 years and produce up to 10 egg sacs during her lifetime, each containing around 250 eggs – a redback infestation can quickly get out of control!

Male redback spider

The male redback is many times smaller than the female. The body is a light brown colour with white markings on the upper side of the abdomen and a pale hour-glass marking on the underside. The red marking are often not as obvious as those on the female.

Males do not build webs and will go searching for a female to mate. The male goes through an elaborate mating process to see whether the female is ready to mate. If he gets this wrong the female will mistake him for prey and eat him! Even if she accepts his mating display and is prepared to mate, as part of the mating process the male offers his abdomen towards her mouthparts to divert her attention during the process. The female then starts to eat the male’s abdomen during mating! Not surprisingly, most males die as a result.

Where do redback spiders live?

They generally like dry sheltered spots to build their webs. Around the home these are the key hiding places:

In sheds and pergolas
Under the outdoor furniture / BBQ
Along fencing
Inside tubular fencing
Under rocks, wood piles and stored goods
In the sub-floor
In the roof void, especially near down lights

Redback spider web

Redback spider webs are not a classic spider web and may be a bit hard to spot. They can often be hidden in holes and crevices – they love the inside of metal tubular fencing! The web looks a bit like an untidy fishing net, often with leaves or debris included. Sometimes an egg sac can be spotted in the web.

Female redback spider with egg sacs — Female redback guarding her egg sacs

Redback Spider Lifecycle

Redback spider eggs

Redbacks build spherical egg sacs, which contain around 250 eggs. These egg sacs will change colour from white to cream as they age. It is not uncommon to see several egg sacs suspended in the web. Female redbacks can become more aggressive than normal when protecting an egg sac.

Baby redback spider (juvenile)

Baby redback spiders are cannibalistic and will eat egg sacs and other redback spiderlings. Young redback spiders, even the females, will have a more mottled colouration, often with additional white markings on the abdomen. Males will mature in around 3 months and females in around 4 months.

How long do redback spiders live?

Female redbacks can live for 3-4 years. Male redbacks only live around 6 months – most will die (get eaten by the female) when trying to mate.

Redback spider diet

Redbacks will eat almost anything that gets stuck in their web, including quite large prey. Although typically they catch insects and other spiders, they also eat small lizards and snakes.

Redback Spiders – FAQ

Can redback spiders kill you?

Yes, redback spiders can kill you. Prior to the anti-venom becoming available in the 1950s there were at least 14 recorded deaths. Although there has only been one recorded death since, this may simply be due to improved health care, as recent research suggests that receiving the anti-venom is no different to receiving a placebo.

What does a redback spider bite look like?

Although most spider bites often create two small holes, where the jaws have pierced the skin, with redback bites, jaw marks are rarely visible. Apart from pain, there will likely be redness, swelling and sweating at the bite site.

How long do redback spider bite symptoms last?

Individual responses to redback bites can be very variable. However, it is not uncommon for the pain to last more than 24 hrs and sometimes symptoms can persist for several weeks.

Should you kill a redback spider?

Redbacks are one of the spiders you should definitely kill if you see on around your home. They are the cause of the largest number of spider bites a year and the most hospitalisations.

How to get rid of redback spiders?

A general insecticide spray treatment around the perimeter of the home and likely redback hiding places once or twice a year will keep redbacks at bay. PestXpert Outdoor Perimeter and PestXpert Spider Blast aerosol are ideal products for spider treatments.

How to kill a redback spider?

The best way to kill a redback spider (if you don’t want to or can’t stamp on it!) is to spray it with a high quality crawling insect spray. (Don’t use a fly spray as it can take a long time to kill the spider). Using PestXpert Spider Blast aerosol will also allow you to get deep into any hiding spots and cover their web, for a guaranteed kill!

How to prevent redback spiders building their webs?

To prevent redbacks moving into your area its necessary to apply a long lasting surface spray to any areas where their are likely to build their webs. Any spider present will be killed directly by the spray and good products will leave a thin layer of insecticide on treated surfaces, to prevent other redback spiders moving in. Make sure the treatment is thorough, to get into the cracks and crevices. For example, spray up the inside of each pole of tubular fencing. In areas more exposed to rain and sun, two applications a year is recommended. PestXpert Outdoor Perimeter is the idea product for this application.

More information on how to control spiders…

Originally Published: August 18, 2019

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