Australia has a reputation for dangerous creatures. Our beaches are notorious for Great White Sharks, Blue Ringed Octopuses, Box Jellyfish, and even crocodiles in the tropics. The bush has a similarly fearsome reputation, with Dingos and six of the twelve most venomous snakes in the world. Even some of our cute wildlife has a deadly side, with Koalas having massive claws and Platypuses having highly poisonous spurs on their heels.
Despite this, the famous Redback spider is probably one of the most iconic deadly Australian creatures – not least because of its notorious fondness for hiding under toilet seats.
What is a Redback spider?
The Redback is one of the world’s most venomous spiders and shares the title of Australia’s most venomous spiders with the Sydney Funnelweb.
teach you what to do.
In some cases, a Redback’s body can be browner in colour, and the stripe can have more of an orange tinge.
For many years, scientists believed the Redback to be closely related to widow spiders such as the black widow, but recent research has found them to be a distinct species native specifically to Australia – related more closely to the New Zealand Katipo spider.
It’s worth knowing that the description above is specific to the female Redback spider – the best known. The male Redback is considerably smaller, at around a quarter the size of the female. It also doesn’t have the large abdomen or red back markings for which the species is famous. They’re also far less venomous than the females and not dangerous to humans – hence they don’t get much press.
Where does the Redback spider live?
Originally native only to parts of South Australia and Western Australia, the Redback can now be found almost anywhere throughout the country. There have also been colonies discovered in Papua New Guinea, New Caledonia, New Zealand and they have even been found in Europe, Japan and America – most likely transported there accidentally by humans.
Redbacks are not migratory – they set up shop in one specific hunting ground and remain there most of their lives. In the bush, this would generally be in a dark hollow in a cluster of rocks or a hollow branch. However, Redbacks are incredibly well adapted to (and show quite a preference for) human buildings and structures – which have an abundance of hiding places suited for them. In particular, their fondness for hiding under toilet seats has become something of an Australian cliché.
This is probably why the Redback has spread so widely and become common since European settlement – our homes and buildings provide them with the perfect habitat. It’s also why Redback spider bites are a reasonably common occurrence in Australia.
How dangerous is a Redback spider?
The bad news is that, as mentioned above, the female Redback is one of the world’s most venomous spiders and one of the few spiders known to have killed humans with a bite. Its venom is highly neurotoxic – meaning it attacks the nervous system. This causes intense pain, and in extreme cases, can disrupt the nerve signals enough to cause paralysis and even death.
The good news is that since the early 1950s, we’ve had an effective antivenom available. Since then, only one person (a Sydney man in 2016) has died of a Redback spider bite in Australia. He’s also the only person in Australia to die of any spider bite since Funnelweb antivenom became available in the 1980’s.
That’s worth remembering – Australia has only had a single fatal spider bite in the last forty years. But it’s also worth remembering that death was a Redback spider bite!
Despite their potent venom, Redback spiders aren’t particularly aggressive. They prefer to hide from threats. Most bites occur when humans accidentally disturb their hiding places and possibly dislodge them. They also have relatively small fangs, so biting a human isn’t super-easy for them – our skin is quite thick from their perspective, and many Redback bites on humans have little effect as they don’t puncture the skin.
What does a Redback spider bite look like?
Redbacks spiders are quite small, as are the bite marks they inflict. A Redback bite will generally be a tiny pinprick puncture wound, or possibly two tiny punctures a millimetre or two apart. In some cases, the bite marks will not be clearly apparent, and the wound might simply appear as an aggravated sore. The bite location will generally be surrounded by an area of red, inflamed skin spreading out from the wound in a rough circle. The area will often show swelling and will generally be quite painful.
It’s common to sweat profusely after a Redback bite. Within around 30 minutes, the pain and swelling from the bite will often have spread throughout the body. And after an hour or so, headaches, nausea and vomiting are also typical symptoms.
What to do if bitten by a Redback spider
The first thing to do is to remain calm – an estimated 10,000 people each year are bitten by Redback spiders, with only one person dying from it the last 70 years. Apply ice or a cold pack to the area to minimise the pain and control the swelling. At that point, you should seek medical assistance. Hospitalisation is not always necessary, but it’s wise to get help.
Avoid anything that applies pressure to the area or cuts blood flow, such as a tourniquet or a bandage with pressure applied. Redback venom spreads very slowly, and applying pressure or restricting blood flow might just worsen the pain.
If possible, you should find and keep the spider that caused the bite so professionals can identify it (in case antivenom is needed). It doesn’t have to be alive – so long as there’s enough left to identify the species. Just be careful not to get bitten again – multiple Redback bites can be more life-threatening.
If you live in an area where Redback spiders are common and you want to be better prepared for a spider bite emergency, the best thing you can do is to invest a day getting properly trained in first aid. A certified first aid training course covers a wide variety of medical emergencies, including recognising the symptoms of different types of spider bite and providing appropriate first aid.