Spiders can be a major cause for concern as venomous bites may cause injury, serious bodily harm and even death. Some people are severely allergic to spider bites and may go into anaphylactic shock, which can be lethal. In Australia, deadly spiders include the Redback Spider and Funnel-Web Spider, however since the introduction of anti-venom, there have been no recorded deaths. Other spiders of concern include the White-tailed Spider, Mouse Spider, Black House Spider and Garden Orb Weaver Spider. Spider webs can also be an unsightly annoyance around the home and garden.
Given the nuisance and potential risk to human health, it is important to control, prevent and monitor for spiders in and around the home.
To control spiders in the home, spray Blitzem! Insect Killer, Blitzem! Concentrate Insect Killer or Blitzem! Outdoor/Indoor Barrier Spray. These products contain a low toxicity but highly effective combination of surface spray insecticides, which will kill spiders and other insects on contact and provide barrier control for 2 - 3 months, in and around the house. Spray onto surfaces, especially into cracks and crevices of: walls, fences, up under the eaves, around door ways, around window frames, along skirting boards, ceilings, along cornices, cupboards, behind sinks and other fittings. Do not apply to fabric.
In the event of a bite or suspected bite, seek medical advice urgently – call Triple Zero (000).
Elderly, sick, immunocompromised, children and pregnant women are most at risk from spider bites.
First aid training is useful for anyone to have, especially if you or someone you know is at a high risk of spider and snake bites.
Spider bite treatment varies according to species and as such, we recommend seeking further medical advice.
Not all spiders are dangerous, most are harmless and quite beautiful. For example, Peacock Spiders are brightly coloured and patterned and perform an elaborate choreographed mating dance. Spiders are also an important part of the ecosystem and help to control garden pests.
Spiders come in a vast array of colours, patterns, shapes and sizes. The largest spider in the world is the Goliath Bird-Eating Spider from South American, with a leg-span of 28 cm.
The head and middle section (thorax) are fused (cephalothorax). At the front of the head region are four pairs of eyes. At the front and underside of the head are a pair of arm-like appendages (Chelicerae) which attach to the fangs. Fangs are generally used for piercing prey and injecting venom. Venom may be used for killing or immobilising prey, and may also liquify the body for later feeding. Another way of liquifying is to spit digestive enzymes on to their prey. Further outwards from the chelicerae are a pair of small antennae-like appendages (pedipalps), used for holding and helping to manoeuvre prey while feeding. On the underside of the cephalothorax are four pairs of legs. Spiders do not have antennae and are wingless.
The rear section (abdomen) is soft and rounded. At the tip of the abdomen are a pair of short appendages (spinnerets) which are used in producing silk. Silk is manufactured inside the abdomen from specialised silk glands. Silk is a sticky, strong and flexible substance which is used for various functions including building cocoons; nests; webs for catching prey; and wrapping their prey. Webs can be spun in a variety of patterns and forms according to the function of the design.
After mating, the female spider spins a cocoon-egg-sac in which the fertilised eggs are placed. Females may lay a few eggs or many hundreds of eggs at a time. Females may leave once eggs have been fertilised or may stay until eggs have hatched. Some females place the egg sac on their backs and carry it around with them.
Eggs may hatch with a few weeks or after many months. After hatching, juvenile spiders (spiderlings) emerge from the egg sac. Spiderlings are similar in appearance to adults, only smaller. Some species carry their spiderlings on their backs. Some spiderlings will run away after hatching while others will ‘fly’ away using single strands of silk elevated and transported by the wind. Spiderlings grow through many stages, shedding skin (moults) at each stage. At full maturity, adults are ready to mate and reproduce. Spiders live for various lengths of time. The longest-lived spider on record, aged 43, is the Australian Trapdoor Spider.
Many species are night dwelling and hide throughout the day. Many ground dwelling species move about after heavy rain or landscaping, for example. Some species wander during the mating season, generally during summer and autumn. Spiders are mostly active during the warmer months and in periods of high humidity.
Spiders primarily feed on other animals (carnivory) such as insects, other spiders, fish, frogs, snakes, lizards, birds and small mammals. However, some spiders may feed on the nectar from flowers.
Outdoors spiders can be found:
Inside the home, spiders can be found near the corners and crevices of a room including:
Ticks, centipedes, other spiders, parasitic wasps, amphibians, reptiles, birds, mammals and even humans.
Evidence of spiders may include:
Depending on the spider’s species, sex, individual, environment and intensity of bite; and also the patient’s age, health status and susceptibility, symptoms of spider bite may include:
At the site of spider bite, symptoms may be:
Prevent from Spiders entering the home:
Reduce the environment favourable to Spiders:
Exclude Spiders from vulnerable items:
How to avoid being bitten by a spider: