Spiders are the most widely distributed venomous creatures in Australia, with an estimated 10,000 species inhabiting a variety of ecosystems.
All spiders are venomous, but most are harmless. Fortunately, only a few of them bite. In fact, the sting of an average bee is much painful than the bites of most spiders.
Spiders are usually very shy and stay hidden in their undisturbed habitat. They are only active at night. They are not even aggressive, and they will try to escape when they are confronted.
Spiders can be very annoying, especially those found inside your home. They love dark, warm and narrow spaces like wall corners, air vents, cracks in walls and eaves of your home. Other species prefer to stay closer to the outdoors, weaving their webs in your garden or near your outside lighting.
Sydney funnel-web
(Atrax robustus)
With highly toxic venom produced in large amounts and large fangs to inject it, the Sydney funnel-web is without a doubt the deadliest spider in Australia, and possibly the world. Found in New South Wales, in forests as well as populated urban areas, they burrow in humid sheltered places. They can wander in backyards and sometimes fall into swimming pools, and though they’re not often encountered, they can be quite aggressive when threatened.
There are about 40 species of funnel-web spiders in Australia, but only six have been reported to cause severe envenomation, with victims generally around southern Queensland and northern New South Wales.
The impressive northern tree funnel-web spider, Hadronyche formidabilis, (4-5 cm long) and the smaller southern tree funnel-web spider, H. cerberea probably count as the most dangerous ones. Half their bites result in severe envenoming.
Redback spider
(Latrodectus hasselti)
Australian spiders 10 most dangerous redback
Redback spiders are found throughout Australia, in many habitats, including urban areas. They often hide in dry, sheltered places such as garden sheds, mailboxes and under toilet seats.
Most serious bites are from the female redback spider, which measures about 1cm long (bigger than males) and is recognisable by the well-known red stripe on its back, from which it gains its name. Their venom affects the nervous system, which is potentially dangerous for humans, but their small fangs make many of the bites ineffective.
Mouse spider
(Missulena sp.)
There are eight species of mouse spider found all across Australia and they’re typically found in burrows, often near rivers or waterways, and can occasionally be found in suburban areas.
Mouse spiders are rather lethargic and rarely aggressive. The females generally remain in their burrow, while the males wander looking for them, generally in late summer to early winter. Unlike other spiders, mouse spiders are often active during the daytime, while other species from the same family prefer to wonder at night to avoid the heat and the day-active predators.
Trap door spiders
(Idiopidae family)
These spiders are named after their habit of camouflaging the entrance of their burrow to trick their prey into falling inside. They measure about 1.5 to 3cm long and as is often the case, females are distinctively larger than males but males tend to be more aggressive when feeling threatened.
Found throughout Australia’s natural or urban environments, trap door spiders cause only minor symptoms for humans, generally inflicting only localised pain, but sometimes nausea, lethargy and malaise.
Just like the mouse spiders, trap door spiders are often mistaken for funnel-web spiders, especially since the early effects of their bites are similar; these spiders should therefore be treated with caution. While most spiders live for about one year, trap door spiders can live between five and 20 years.
White-tailed spiders
(Lampona cylindrata and L. murina)
Lampona cylindrata is found in natural and urban areas across southern Australia, from south Queensland to Tasmania and from east to west coast, and Lampona murina in eastern Australia. Unlike burrowing spiders, white-tailed spiders are vagrant hunters and wander about at night, hunting other spiders.
Though white-tailed spiders have a reputation for releasing necrotising (flesh-eating) venom, the scientific evidence doesn’t support this assertion. More likely, the spiders were wrongly held to blame for difficult to diagnose skin ulcers. Recent studies have shown the venom causes no major danger to humans and is limited to mild local pain.
Australian tarantulas
Australia has its own native tarantulas, though they’re also known as whistling or barking spiders because of the sounds some species can produce by rubbing their front limbs against their jaws. They are also called bird-eating spiders, although it is rarely justifiable. These spiders mostly feed on insects, including other spiders, lizards and frogs and would occasionally prey on bird hatchlings.
Four genera, Selenocosmia, Selenotholus, Selenotypus, and Phlogiellus are generally found throughout the country. Only six species have been officially identified, though it’s likely many more exists. Despite their intimidating large size and hairy legs, (6cm body and up to 16cm legspan) tarantulas aren’t fatal to humans; they can render painful bites because of their large fangs (1cm long), but severe effects (nausea, vomiting, fever) are rare. They can, however, kill dogs. Females live for about 12 years and males about five.
Recluse spider
(Loxosceles reclusa)
Also known as a fiddleback spider, the recluse spider has potentially dangerous venom that can be haemotoxic, damaging the blood and skin as well.
In 20 years that fiddleback spiders been known to exist in Australia, their range hasn’t increased and not a single envenomation case has been reported here, so despite the myth, this spider can hardly be considered dangerous in Australia – though they are a major cause of serious bites in South America. Moreover, they are known to only have tiny fangs to inject their venom and are not inclined to bite.
Huntsman spiders
(Sparassidae family)
Huntsman spiders are widespread in Australia. They are famous for being the big (up to 15cm leg-span) scary, hairy, black spiders bolting out from behind the curtains. In reality, they are reluctant to bite and more likely to run away when approached and their venom isn’t considered dangerous for humans.
Their danger comes more from causing accidents by the terrified drivers who react to a huntsman jumping out from behind the sun visor or dashboard of a car when it’s in motion. Despite their intimidating size, huntsman spiders can be an ally in the house; they help with pest-control by eating smaller insects.
Common garden orb weaver spider
(Eriophora sp)
As the name suggests, common garden orb weave spiders are a typical sight around Australia. Their bites have only minor effects, such as some local pain, but they are aggressive: they’re the most common spider species to bite.
They measure between 1.5cm and 3cm and live in all the gardens, generally weaving webs between trees, on hedges or washing lines, in places where other insects are likely to fly and get caught in the sticky threads. Active at night, they hide during the day and rest with their legs withdrawn under the body, hanging off a thread under a leaf or in the clothes hanging from the line.