Snakes and spiders have a well-deserved reputation as two of the most venomous creatures you’re likely to meet, and Australia has is well known for having plenty of both.
Spiders, in particular, tend to make foreign visitors nervous. While snakes are occasional visitors in the suburbs (with professionals often called in to remove them), spiders are found in almost every suburban house. Generally, people who grew up in Australia have a healthy respect for them and just adapt to garden sheds having tiny creatures that could (theoretically) end your life. This is something that a lot of international tourists struggle to grasp.
But despite our reputation for deadly wildlife (and the spider’s role in that), how much risk are we truly at from spider bites? What are the odds of suffering poisoning and death from spiders under our outdoor furniture?
When do spiders bite, and why?
Let’s start with how likely a spider is to bite. The reality is that no spider in Australia regards humans as its prey. So you’re never going to have a spider come looking for you as something to eat (not even a “Bird Eating” spider would hunt a human). In Australia, almost all bites result from a spider feeling threatened – most commonly when someone accidentally approaches or puts a hand in a spider’s hiding place.
Even in those cases, the majority of spiders are reluctant to bite. This is true even of the Redback – probably the most famous Australian spider. Redbacks prefer to escape from danger and only tend to bite as a last resort (such as when someone sticks their fingers in the hole it’s hiding in).
It is true that some spiders respond to threats (like a nearby human) by going on the offensive. The most significant of these is the Funnelweb, which has a reputation for chasing people to bite them (and is sometimes capable of biting through shoe leather). But even these are responding to a perceived threat – they’re not looking for trouble.
What spider bite can kill you?
The Sydney Funnelweb lives mainly on the east coast of NSW, with a few found in neighbouring states like Queensland, SA, and Victoria (and even Tasmania). They make distinctive webs – a tube of spiderweb that radiates out into a funnel of web-strands – giving the species its name. Male Funnelwebs are known for wandering at night (in search of food and mates), which is often when they cross paths with humans.
Redbacks live almost everywhere in Australia that humans do. They’re particularly fond of living in human structures – and indeed, they seem to have become far more common since Europeans settled in Australia, and have spread along with the settlers. As such, there are good odds of finding at least one on any Australian property. But they’re reluctant biters and generally only do so as a last resort.
No other Australian spiders have ever killed humans (with the possible exception of road accidents caused by unexpe). Some can still cause poisoning, resulting in pain, nausea, headaches, and other unpleasant symptoms. But most won’t even do that – the bites of most Australian spiders will do you no more harm than a bee-sting.
In fact, it’s worth noting that almost no one in Australia dies from spider bites nowadays. Since the development of an effective Redback antivenom in 1956, there has been only one death from a Redback bite – a Sydney man who died in 2016). And there have been no recorded Funnelweb-bite deaths since the antivenom was introduced in 1981.
Meaning in the last 40 years, only one person in Australia has died from being bitten by a spider.
What does a spider bite look like?
Spider bites are unfortunately not always easy to distinguish from other types of bite, such as those from an ant or other insect. There will generally be a small red lump at the bite location, which may itch or sting. In some cases, there may be a tiny puncture wound – or two, very close together, but not always. And again – this is true of many insect bites. It may not even be clearly a bite, appearing more like a sore (especially if some skin is scratched away due to the itching). In many cases, it doesn’t matter, as the majority of spider bites are no more medically significant than an ant bite. For more significant bites, there will generally be other symptoms.
Some spider bites may cause significant pain at or around the wound. Victims may also suffer nausea, headaches, abdominal pain, and vomiting. More severe bites may cause sweating, with swelling or blistering around the wound, and a burning sensation.
Redback spider bite symptoms often include the area around the bite becoming inflamed, painful to the touch, and swollen. They can also cause sweating and muscle weakness or spasms.
For a Funnelweb bite – the most dangerous kind of spider bite – the bite itself will generally be very painful. Funnelwebs are large spiders with big fangs. In addition to more common spider bite symptoms, victims might find themselves drooling and can have difficulty breathing, muscular spasms, numbness in the mouth, goosebumps, tears, disorientation or confusion, a fast pulse rate, and eventually fall unconscious.
If possible, catching the spider that caused the bite (dead or alive) can be a big help, as being able to identify the spider makes treatment a lot simpler. If you can’t catch it, then taking a photo of it or at least taking careful note of its appearance can help. But be careful not to get bitten in the process!
What to do for a spider bite
The best treatment for a spider bite depends a lot on the kind of spider that caused the bite. Medically spider bites in Australia fall into three categories.
- Big Black Spiders
- Any Other Spiders
Big Black Spiders covers anything that could potentially be a Funnelweb – which are large spiders with bodies up to 5cm long. Because Funnelwebs are highly venomous and hard to distinguish from other large black spiders, treat any large black spider bite as a potential Funnelweb bite. You should call for medical assistance ASAP – Funnelweb venom is very fast-acting. Big Black Spider bites should be treated by applying pressure to the wound and using a pressure bandage (and possibly a splint) to limit blood flow and avoid the poison spreading. Keep the person still as much as possible.
The best treatment for most other types of spider bite is generally to apply something cold, like an ice-pack wrapped in a cloth. This is true even for Redback bites – Redback venom is very slow-moving, and most Redback bites do not require hospital unless symptoms get a lot worse.
If anyone in the area has first aid training, you should seek out their help if possible. Professional first aid courses usually cover spider bites and how to identify and treat them. If you’re in an area where spiders are commonplace, this might be a good reason to invest a day in getting proper first aid training yourself.
When to go to the hospital for a spider bite (or call 000)
For a confirmed Big Black Spider bite (or a bite where you don’t know the spider but you’re seeing Funnelweb bite symptoms), you should call 000 immediately. Funnelweb venom works very quickly – in small children, death can occur in as little as 15 minutes. However, the time for adults is generally longer – up to three days – and not all bites are life-threatening. It’s best to call for an ambulance rather than attempting to transport the person to hospital yourself, as moving the person around (into and out of the car) could spread the venom more quickly.
For a Redback bite, the majority of cases don’t require medical care (other than first aid). The bite should be iced to control swelling and discomfort, and you can use painkillers such as paracetamol to ease the pain. Keeping the victim still and calm is also helpful. Don’t apply pressure to a Redback bite, as the venom is already slow-moving, and pressure will just cause pain for the victim.
If the symptoms get worse (such as the swelling spreading or the victim sweating or suffering pain in the chest or abdomen), then it’s a good idea to get to the ED (or call 000 for an ambulance).
For most other spider bites, all you need to do is help ease the person’s symptoms (with an ice pack and and painkillers) unless their condition gets significantly worse.
The big exception to all this is if the victim starts to show signs of anaphylaxis – such as trouble breathing, swelling or tightness in the throat, or a swollen tongue. If this happens, you should call 000 immediately.
How long does a spider bite take to heal?
For most spider bites, symptoms should only persist for a day or so, although occasionally they can last significantly longer – up to 2-3 weeks in rare cases.
Redback spider bite symptoms generally last around 24 hours on average and rarely last more than a week.
Funnelweb bites are more significant and can victims take a while to recover fully. Before 1980, victims would generally be in hospital for an average of two weeks. However, this has changed now an effective Funnelweb antivenom is available, and patients are often discharged from hospital within 1-3 days.