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Common Australian Spiders – How dangerous are they?

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Australian spiders have quite a reputation around the world. As a nation, we’re pretty light on for bears and wolves and large creatures that can eat you. But we are pretty well known for deadly creatures that live in toilet seats and under bin handles.

But how dangerous ARE Australian spiders? What Australian spiders can kill you, which ones will poison you, and are there spiders we don’t need to worry about? Let’s look at some of the most common Australian spiders and just how dangerous they are.

A few facts about Australian spiders

First, let’s get a few basic facts straight about Australian spiders.

  • Only two Australian Spiders can kill humans – It’s true. In the last two centuries, only two Australian spiders have ever killed people with a bite – the famous Redback spider, and the Sydney Funnelweb. And we now have antivenoms for both types of bite.

  • Almost no one dies from spider bites – As weird as this may sound, it’s pretty well documented. In the last forty years (since the development of a Funnelweb antivenom), there has only been one death from a spider bite in Australia.

  • Most are poisonous, few are dangerous – Almost every Australian spider has some type of venom, but very few of them are particularly harmful to humans. Also, most spiders are very reluctant biters, doing so only as a last resort (such as when a human jams their fingers into their hiding spot). Even the aggressive spiders that chase humans only do so when they feel threatened.

  • Spiders are less dangerous than bees – This might seem bizarre, but the numbers are hard to argue with. In 2017-2018, 12 people died to bee and wasp stings, versus no deaths for spiders. While it’s true that some spiders have far more toxic venom, the fact that bee stings are a very common trigger for anaphylaxis gives them the clear lead here.

With some of those facts under our belt, let’s have a look at some common Australian spiders and see just how dangerous they are.

Australian House Spiders

A distressing fact of life in Australia for many tourists and arachnophobes is that most Australian houses have a fair supply of spiders around the place. Fortunately, most of them are just there for the bugs, and the majority aren’t that dangerous. Here are a few that you might come across in your travels.

Daddy-long-legs

Daddy Long Legs
They’re not the biggest
spider around!

Daddy long legs are one of the most common spiders you’re likely to meet in the house. They often like to hide under furniture or up high near the roof. They’re also hard to see (their bodies are tiny, and their legs are super thin), and because they’re generally regarded as harmless, many people don’t bother dislodging them until they start to look untidy.

There’s an old story that Daddy long legs have the world’s most deadly venom, but don’t kill humans because their fangs aren’t long enough to get through human skin. Neither is accurate, and Daddy long legs actually have venom that’s almost entirely harmless to humans. Although, ironically enough, these tiny spiders are surprisingly good at catching and eating other spiders – including Redbacks!

Huntsman spiders

These rather large hairy spiders are pretty common in Australian households. Arachnophobes particularly hate them due to their size (they can be as big as your palm), speed, and their tendency to lurk in plain sight on walls and ceilings. In reality, Huntsmen are relatively harmless to humans. If threatened, they can be aggressive, and their bites can be painful (they have pretty big fangs). But generally, the worst effects of a Huntsman bite is pain at the bite site and other side effects like nausea and headaches.

They can occasionally cause road accidents by appearing in cars at unexpected moments. But given they’re reasonably harmless and quite large, some people choose to leave alone – to keep insects under control. Some even give them names.

Redback spiders

This is possibly the most famous Australian spider, it can be found in most Australian houses, and it’s one of the two that can kill – Redback bites can be fatal to humans. They’re generally about the size of a 10c coin and shiny black with a brilliant red stripe on the back. Redbacks have become far more common with white settlement, as the dark corners of our buildings are perfect for them. Redbacks tend to stay in the same spot most of their adult lives.

They’re reluctant biters but will do so if threatened. Unfortunately, their tendency to hide in wheely bin handles and (notoriously) under toilet seats means this happens reasonably often when humans unknowingly invade their space. Their bites are slow spreading, but inflamed and painful, often with many other significant side effects – such as sweating and muscle spasms. Bites don’t always require hospitalisation, but it’s definitely worth getting medical advice if someone’s been bitten.

Only the female redback is dangerous. The male redback is around a quarter the size, isn’t dangerous to humans, and generally gets eaten by the female after (or sometimes during) mating.

Black House Spiders

These are squat little black spiders about the size of a 5c piece. They’re relatively fond of human houses and make unusual webs with a curved, funnel-like shape. Like Redbacks, they tend to pick one area as their home / hunting ground and stay there most of their lives – repairing their webs when needed. Their bites are painful and can cause swelling, nausea, and sweating, but they’re not actually dangerous. They’re also reluctant to bite if they can escape instead.

Cupboard spider (aka Brown House Spider)

Cupboard spiders are small dark spiders – the female can sometimes be mistaken for a redback spider, although they lack the trademark red stripe. Their bites can be painful and cause swelling and sometimes nausea and sweating, but they’re not lethal like a redback is.

White-tailed spiders

White-tails are small, dark, elongated spiders with a distinctive white patch on the end of their abdomen. They have an awful reputation nowadays, which is almost entirely undeserved. The internet myth is that the bites of white-tailed spiders cause necrosis – making the flesh around the bite rot and die. As it turns out, it’s pretty much made up. White-tailed spider bites cause some pain and irritation around the bite and possibly some nausea and headaches, most of which should resolve within 24 hours. Although in some cases, the bite may be irritated for a week or so afterwards.

White tails don’t make webs, and they’re known for eating far more harmful spiders – including Black House Spiders and Redbacks. They do have a fondness for hiding in the folds of clothing, though – so if there are white-tails around, then it might be a good idea to shake out any shirts you leave on the floor.

Outdoor Spiders

Many Australian spiders don’t love human settlements, preferring to stay in bushland – or out in the garden.

Garden orb weaving spiders

Australian Orb spiders (such as the orb weaver) are large, brown or grey spiders around the size of a 20c coin with stocky, heart-shaped abdomens. They can often inadvertently cause problems for humans due to their tendency to build large webs – making a new one each day. These are often built through an open part of the garden and anchored to nearby trees and bushes. Which sometimes means the web is right over a path or walkway, and humans can walk directly into the web – occasionally with the spider sitting in the middle, at around face height.

Other than this alarming habit, they’re very little threat to humans – they’re reluctant biters, they’re not aggressive, and their bites generally only cause mild pain and swelling and sometimes mild discomfort or nausea.

Australian Wolf Spiders

Wolf spiders are large, furry spiders not totally dissimilar to a Huntsman, which are found all over Australia and are common to much of the world. The Australian Wolf Spider (like most of its kind) is a ground feeder that doesn’t make webs. They hunt and eat insects and even some larger animals on the ground, but they make burrows to hide and rest.

Although they can look rather intimidating, wolf spider bites have only mild effects on humans – localised pain or itching, swelling, and potentially some dizziness or nausea.

Saint Andrew’s Cross Spider

This is probably a contender for the most artistic spider on the list. Like Orb Weavers, Saint Andrew’s Cross Spiders make large webs spanning open areas between trees and bushes. Unlike the Orb Weaver, the Saint Andrew’s Cross constructs it’s web with a large, highly distinctive strip of lace-like web in an “X” pattern at the centre. The spider itself tends to sit at the middle of this x shape, generally with it’s eight legs also held in a cross shape. These two elements create the distinctive cross image that gives the spider its name. The spiders also have visually striking patterns on their bodies, which reflect UV light – to attract insects.

Like orb weavers, they’re reluctant biters, and their bite isn’t dangerous – similar in pain and discomfort to a bee-sting.

Big Black Spiders

Large black spiders are treated with special care by medical professionals. Not because they’re ALL dangerous (they’re not) but because many big black spiders look similar to the Sydney Funnelweb – which is one of the two lethal Australian spiders. So most medical personnel will treat ANY large black spider bite as a potential Funnelweb bite.

Funnel Web Spider

This is possibly the most dangerous spider in Australia, both due to its highly deadly venom and also its tendency to go on the offensive when threatened – not to mention having fangs large enough to bite through shoe leather. Funnelweb bites are painful, and their venom is potent and fast-acting. It can often cause unusual effects, such as drooling, goosebumps, tears, muscular spasms, and elevated pulse and disorientation. Call 000 immediately for a Funnelweb bite – don’t muck around!

Fortunately, the development of Funnelweb antivenom has meant there have been no actual Funnelweb deaths since 1981.

Funnelwebs are large, stocky, furry black spiders that can be as big as your palm. They live mainly on the east coast of Australia but have been occasionally found in other states. They’re named for the distinctive funnel shape of their webs. Females generally stay inside their webs, while males tend to wander in warmer months, looking for females to mate with – which is generally when they encounter humans.

Trapdoor Spider

Trapdoor spiders are large furry black spiders similar in appearance to a Funnelweb. They’re named for the way they often build their tube-shaped burrows with a “hatch” at the entrance, allowing them to ambush prey. Despite looking like one of our planet’s deadliest spiders, Trapdoor spiders are actually relatively harmless – their bites generally only cause local pain and swelling. But unless the spider has been verified as a Trapdoor spider by an expert, you should treat the bite like it’s a Funnelweb bite – call 000 as soon as possible.

Mouse Spiders

Mouse spiders are another big black spider, similar to a Funnelweb but with a shinier carapace and a more bulbous head and jaw. They’re common to most urban areas – including the south and west coast. Their bite is quite harmful, causing serious pain and severe poisoning – but fortunately, they’re wary of biting, and they’re believed to use less venom than a Funnelweb, and sometimes “Dry bite” (digging fangs in, but not injecting venom). Funnelweb antivenom is also effective against Mouse Spider venom, and because of their similarity to Funnelwebs and the potency of their venom, they should be treated just like a Funnelweb bite.

Spider First Aid

Ultimately, the best way to be prepared for spider bites is to get first aid training – which, in addition to preparing you for a wide variety of other medical emergencies, will provide a solid grounding in how to recognise and respond to stings and bites such as spider bites

Medical personnel tend to break spider bites down into three categories for treatment – basically based on whether the bite might be a Funnelweb or Redback bite.

  • Big Black Spider bites – Immediately call 000. Use pressure – such as a pressure bandage – to slow down blood flow around the bite and restrict blood flow. Where possible, keep the person still and calm.
  • Redback bites – Use an icepack to reduce swelling and pain around the bite. Pressure isn’t needed, as Redback venom doesn’t spread quickly, and you’ll just cause unnecessary pain. Call 000 if symptoms worsen over time.
  • Other spider bites – Generally, the only intervention needed is an icepack to lessen pain and swelling and potentially painkillers such as paracetamol to ease symptoms. The victim should only require Medical assistance if symptoms get significantly worse.

The exception to these guidelines is if the bite victim shows any sign of an anaphylactic reaction, such as swelling or tightness in the throat, a swollen tongue, or difficulty breathing. In these cases, it’s time to call 000 immediately – and possibly administer adrenaline if the person has an EpiPen or AnaPen with them.

Article by Lochy Cupit
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