Spiders are members of the class Arachnida
. Other members include ticks, mites and scorpions. Generally, spiders have eight legs, two-part bodies, fangs, and organs that spin webs. Spiders are essential to our ecosystem as they prey on insects and keep their populations under control.
Australia has about 2,000 species of spider, but most are relatively harmless to humans. Funnel-web spiders (indigenous to Sydney) and red-back spiders (found throughout the country) are perhaps the most venomous spiders in Australia.
Since the introduction of antivenom, there have been no recorded deaths in Australia from a confirmed spider bite.
Spider bites and venom
Most spiders have venom. A spider uses venom to paralyse its prey – usually flies and other insects. However, a spider that feels frightened or threatened by a human may bite. In most cases, spider fangs are not strong enough to break the skin. If the fangs do break the skin, the venom usually has no effect on the human body. The pain of most spider bites can be managed with an icepack.
The few Australian spiders that can cause potentially harmful bites include the funnel-web, the mouse, the red-back and the white-tailed spiders. People at greater risk of severe reactions to spider venom include babies, young children, the elderly and people with an existing heart condition.
Some people may also be allergic to certain venom and experience an adverse reaction. Immediate medical treatment is recommended. If in doubt, see your doctor, go to the emergency department of your nearest hospital or dial triple zero (000) to call an ambulance.
Antivenoms are available for the treatment of red-back and funnel-web spider bites.
Symptoms of spider bites
Symptoms of a venomous spider bite depend on the species, but may include:
- Redness and itching
- Increasing pain
- Sweating (perspiring)
- Dilated pupils
- Uncontrollable muscle spasms
First aid for spider bites
Remember that first aid for a venomous spider bite depends on the species of spider. Suggestions include:
Funnel-web and mouse spider
– firmly bandage the affected area. Splint if possible. Make sure the person lies still, because not moving will help to slow the venom moving through the body.
Red-back and white-tailed spider
– wash the bitten area thoroughly. Do not bandage because pressure will increase pain. Apply an icepack.
In all cases, never cut a spider bite or tourniquet a limb. Don’t give the person anything to eat or drink. Seek immediate medical help.
Catch the spider, if possible
If you can, catch the spider and take it with you to hospital so that medical staff can identify the species and quickly administer the correct treatment. Tips on how to safely catch a spider include:
- Choose an empty container with a secure lid, like a jar.
- Place the container over the spider.
- Slide a piece of stiff cardboard beneath the container to seal it.
- Hold the cardboard securely and turn the container upside down. The spider should drop to the bottom of the container.
- Remove the cardboard and attach the container lid.
If you cannot catch the spider, it will help medical staff if you can describe it. Features to look for include size, colour, bulk and where the spider was when it bit you.
Favoured locations of venomous spiders
To assess your family’s risk of spider bites, familiarise yourself with the kinds of spider that tend to live around your home and garden. Each species of spider has a preferred home or hunting ground.
Signs you should look for include:
- Funnel-web – found along the East Coast from Queensland to Tasmania and in some areas of South Australia. It likes to live in holes in moist soil, such as in mulched garden beds. Erratic (rather than symmetrical) web lines may fan out from the hole. Males tend to roam for females in autumn and summer. The funnel web is nocturnal (comes out at night). The male Sydney funnel-web is considered to be Australia’s most dangerous spider, and is the only type of funnel-web responsible for recorded human deaths. The Sydney funnel-web is not found in Victoria.
- Mouse – found all over Australia. It likes to live near water in ground holes that feature right-angled ‘trap doors’. Males are coloured either red on the jaw or bluish-white on the abdomen. Females are larger than the males.
- Red-back – found across Australia, but is less common in cooler climates. It looks shiny black with a red or orange marking on the abdomen. Only the female bite is venomous. The red-back does not live in the ground; instead, it chooses ‘man-made’ sheltered areas such as inside sheds or beneath stairs. The web is usually made in the shade. The top of the web contains a thickly spun ‘cone’, where the spider sits. Red-backs are not aggressive. Most bites occur when people accidentally put their hand in the web and the spider feels threatened.
- White-tailed – found across Australia. It is coloured grey to black with a white patch on the abdomen. It does not build a web. The white-tailed spider is commonly found in cool and tiled areas such as bathrooms and laundries, and may hide inside shoes, clothes and other items left on the floor. Outdoors, it lives under bark and logs and in leaf litter. It is nocturnal.
Common but relatively harmless spiders
Some spiders may look scary, but are not dangerous to most people. Common examples include:
- black house – found in eastern and southern Australia. It may be found under tree bark and around windowsills. The webs are formed in messy ‘sheets’
- huntsman – likes to live under bark, rocks and crevices. The two front pairs of legs are much longer than the back two pairs of legs. Despite its size, a huntsman is usually harmless. A bite, however, may cause some swelling and pain
- wolf – found across Australia. It is coloured brown to grey. The wolf spider has a distinctive set of six ‘eyes’ at the fore of its body. Typical symptoms of a wolf spider bite include some itching and pain.
Tips on avoiding spider bites
- Always wear gloves, long trousers and shoes while gardening.
- Wear shoes when walking around in the garden.
- Inspect any suspected spider web or lair with a stick (or something similar), not your hands.
- Shake out shoes before you put them on.
- Don’t leave clothes on the floor – if you do, shake them out before you put them on.
- Instruct children not to touch spiders.
- Don’t assume that a spider at the bottom of a swimming pool is dead. Some spiders can survive on an air bubble for 24 hours or more.
Spider-proof your home
It may be impossible to eradicate spiders from your garden, but you can stop most spiders from living in your house. Suggestions include:
- Clear away trees, shrubs and bushes from around doors or windows.
- Avoid the use of insecticides in the garden, as spiders may be encouraged to flee into the house.
- Fit draught-strips to all doors. Spiders may crawl in under doors.
- Install flyscreens to windows and any vents, such as wall ventilation slots.
- Don’t leave equipment or clothing (such as shoes) outside. If you do, shake out before you wear them or bring them inside the house.
- Keep the windows of your parked car wound up to avoid being surprised by a spider while you’re driving.
- Pour boiling water (from a kettle) into any spider holes you find near doorways and windows. This will kill the spider.
- Consult with a licensed pest control operator for professional advice.
Where to get help
- Your doctor
- In an emergency, call triple zero (000)
- Emergency department of your nearest hospital
- Australian Venom Research Unit Tel. 1300 760 451
- Local council
- Licensed pest control operator
- Department of Health and Human Services, Pest Control Team. Tel: 1300 767 469
- The Australian Environmental Pest Managers Association Tel. 1300 307 114
- Victorian Poisons Information Centre Tel. 13 11 26 – seven days a week, 24 hours a day – for advice about poisonings, suspected poisonings, bites and stings, mistakes with medicines and poisoning prevention.
Things to remember
- Australia has about 2,000 species of spider, but most species are relatively harmless to humans.
- Install flyscreens on windows and weather-strips on doors to stop most spiders from entering your house.
- Seek immediate medical help for bites from a funnel-web, mouse, red-back or white-tailed spider.
This page has been produced in consultation with and approved by:
Department of Health and Human Services - RHP&R - Health Protection - Environmental Health Unit
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