Spider fact sheet | Field of Mars EEC

What are spiders?

Spiders are arachnids. Adult spiders have two main body sections, eight legs, pedipalps, fangs and spinnerets that make silk. Most spiders also have eight eyes, although the size and arrangement of the eyes is different in different groups.

Spiders are predators. Some spiders build webs to catch their prey, while others hunt on the ground, leap onto insects, ambush prey from leaves or wait near burrow entrances. Spiders are an important part of bushland food webs because they help control insect numbers and provide food for other animals.

At Field of Mars Reserve, spiders can be found in leaf litter, under bark, on tree trunks, among shrubs and grasses, beside creeks and wetlands, in webs, in silk-lined burrows and in sheltered cracks.

A trapezoid spider.

Some spiders rest on plants and use camouflage to hide from predators and prey.

Where do spiders live?

Spiders live in many different habitats. Some live on the ground in leaf litter or burrows. Others hide under bark, rest on leaves, build webs between shrubs, live in folded foliage or hunt on tree trunks.

The Field of Mars Reserve has many spider habitats, including eucalypt forest, fallen logs, bark, shrubs, grasses, leaf litter, creeks and wetland edges. Moist places near creeks can support spiders such as silver orb-weaving spiders and net-casting spiders. Drier forest and woodland areas provide shelter for trapdoor spiders, hunting spiders, triangular spiders, crab spiders, wolf spiders and web-building spiders.

When looking for spiders, observe carefully and do not touch. Spiders may be found on paths, plants, bark, logs, low vegetation and webs, especially after rain or at night when many species are active.

Trapdoor spiders live in silk-lined burrows in the soil. Some species build a camouflaged door at the entrance.

What do spiders eat?

Spiders are predators. Most spiders eat insects such as flies, moths, beetles, mosquitoes, ants, grasshoppers and other small invertebrates. Some spiders also eat other spiders.

Different spiders catch food in different ways. Orb-weaving spiders use round sticky webs. Net-casting spiders hold a small silk net in their front legs and throw it over passing prey. Jumping spiders use their excellent eyesight and leap onto prey. Crab spiders, triangular spiders and trapezoid spiders sit still on flowers or leaves and ambush insects that come close.

Spiders usually use venom to subdue their prey. They then feed by sucking up the liquid parts of the prey’s body.

Many web-building spiders wrap their prey in silk before feeding.

What is the life cycle of a spider?

A female spider lays eggs and covers them in silk to make an egg sac. The egg sac helps protect the eggs from drying out, predators and damage. Depending on the species, an egg sac may be hidden under bark, placed in a web, attached to vegetation, made inside a burrow or guarded in a silk retreat.

Spiderlings hatch from eggs and often stay together for a short time. As they grow, spiderlings moult. Moulting means shedding the hard outer skeleton so the spider can grow a larger one. After several moults, the spider becomes a juvenile and then an adult.

Some spiderlings disperse by releasing silk into the air. The wind can carry the silk thread and the tiny spiderling to a new habitat. This is called ballooning.

Spiderlings hatch from eggs inside a silk egg sac.

What adaptations do spiders have to help them survive?

Spiders have many adaptations that help them catch prey, avoid predators and survive in their habitat.

Spinnerets produce silk that can be used for webs, shelters, egg sacs, safety lines and wrapping prey. Some spiders use camouflage to blend in with bark, leaves, flowers or leaf litter. Wolf spiders run quickly across the ground. Jumping spiders have large front eyes and strong back legs for leaping. Orb-weaving spiders build sticky capture webs. Net-casting spiders have very large forward-facing eyes for hunting at night. Triangular spiders, crab spiders and trapezoid spiders wait motionless with strong front legs ready to grab prey.

These adaptations allow different spiders to live in different parts of the same bushland habitat.

Spinnerets produce silk used for webs, shelters, egg sacs and safety lines.

Are spiders dangerous?

Most spiders should be left alone and never handled. Many spider bites only cause local pain, redness or swelling, but some Australian spiders can be medically important.

In Sydney, students should be especially careful around large dark spiders that could be funnel-web spiders, and around redback spiders in dry sheltered places. A spider should not be identified by students unless an adult or expert confirms it.

If a spider bite occurs, tell an adult straight away. If a funnel-web spider bite is suspected, call Triple Zero (000), keep the person still and use pressure immobilisation first aid while waiting for medical help. Do not use pressure immobilisation for other spider bites unless directed by medical advice.

Sydney funnel-web spiders should never be touched or handled.

Why are spiders important?

Spiders are important predators in bushland, gardens and other ecosystems. They help control insect numbers, including flies, mosquitoes, moths, beetles and plant-feeding insects.

Spiders are also food for many animals. Birds, lizards, frogs, wasps and other predators may eat spiders. Some wasps even hunt spiders to feed their young.

A bushland habitat with many kinds of spiders has predators working in many different places, including leaf litter, tree trunks, shrubs, grasses, flowers, webs and burrows. This helps keep the food web balanced.

Spiders catch insects and other invertebrates and are part of the bushland food web.

How can you help spiders?

You can help spiders by protecting their habitat. Leave leaf litter, logs, bark and branches in safe bushland areas because many spiders shelter, hunt or lay egg sacs there. Grow native shrubs and grasses to provide places for spiders to build webs and hide.

Avoid breaking webs, spraying unnecessary pesticides or handling spiders. During fieldwork, watch spiders carefully without touching them. If a log, rock or piece of bark is moved for observation, place it back gently so animals can continue to use the habitat.

Spiders are useful animals. The best way to learn about them is to observe their shapes, webs, behaviour and habitats from a safe distance.

Leaf litter, bark, logs and native plants provide shelter for spiders.

Common spiders in Sydney bushland

The Field of Mars Reserve is part of Sydney’s bushland and includes eucalypt forest, shrubs, leaf litter, creek lines and wetland edges. The spiders below are common, widespread or well-suited to Sydney bushland, gardens and nearby natural areas.

Triangular spiders

Triangular spiders, including the common triangular spider, have a small body with a triangular or heart-shaped abdomen. Many are brightly coloured or patterned. They usually sit on or under leaves and wait for insects to come close.

Triangular spiders do not build a web to catch prey. Instead, they use silk as a safety line and pounce on small insects from leaves, shrubs or tree trunks.

Triangular spiders are ambush hunters that often rest on leaves.

Trapezoid crab spiders

Trapezoid crab spiders, also called trapezium crab spiders, have a wide, angular body and spiny legs. They are usually found on flowers, leaves or foliage where they wait for insects.

These spiders are ambush hunters. Their body shape and colours help them blend in with plants.

Trapezoid crab spiders wait on plants and grab insects that come close.

Silver orb-weaving spiders

Silver orb-weaving spiders are small, shiny spiders with silver, green, yellow or black markings. They often build delicate webs among low plants, shrubs and moist vegetation.

These spiders catch small flying insects in their webs. They are often found near creeks, wetlands, gardens and bushland edges.

Silver orb-weaving spiders build delicate webs among low vegetation.

Long-tailed silver orb-weavers

Long-tailed silver orb-weavers are slender orb-weaving spiders with a long, tapering abdomen. They build orb webs in low vegetation and use their web to catch flying insects.

Their body shape and silvery colours can make them difficult to see among grasses and shrubs.

Long-tailed silver orb-weavers are slender spiders that build orb webs in vegetation.

Trapdoor spiders

Trapdoor spiders are ground-dwelling spiders that live in silk-lined burrows. Some build a camouflaged door at the entrance, while others have an open burrow.

They usually wait near the burrow entrance at night and rush out to catch insects and other small invertebrates. Female trapdoor spiders may stay close to their burrow for much of their life, while males are sometimes seen wandering after rain or in warmer weather.

Trapdoor spiders live in silk-lined burrows in the ground.

Yellow sac spiders

Yellow sac spiders, including the common garden sac spider, are pale yellow, cream or light brown hunting spiders. They often make a silk retreat in folded leaves, bark, grass tussocks or sheltered spaces.

They usually hide during the day and hunt at night. They are common in gardens and nearby bushland in eastern Australia.

Yellow sac spiders make silk retreats and hunt at night.

Garden orb-weaving spiders

Garden orb-weaving spiders are common in gardens, forests and bushland edges. They build large circular webs at night to catch flying insects such as moths, flies and beetles.

During the day they often hide on nearby leaves, bark, fences or branches. Some garden orb-weavers rebuild or repair their webs each evening.

Garden orb-weaving spiders build large circular webs at night.

St Andrew’s Cross spiders

St Andrew’s Cross spiders are orb-weaving spiders with silver, yellow, black and brown markings. Many build an X-shaped pattern of white silk in the centre of their web.

They are often found in low shrubs, gardens, grassland and bushland edges. The white silk pattern may help protect the spider or make the web more visible to larger animals.

St Andrew’s Cross spiders often rest with their legs held in pairs.

Golden orb-weaving spiders

Golden orb-weaving spiders are large web-building spiders. Their strong webs often have a golden colour in sunlight and may be built between trees, shrubs or other supports.

Golden orb-weaving spiders catch flying insects such as flies, beetles, moths and cicadas. Their webs are strong and should be watched without touching.

Golden orb-weaving spiders build large, strong webs between plants.

Net-casting spiders

Net-casting spiders are nocturnal hunters. They make a small silk net and hold it with their front legs. When an insect walks past, the spider stretches the net over the prey.

Net-casting spiders have very large forward-facing eyes that help them hunt in low light. They often rest stretched out along twigs or bark during the day.

Net-casting spiders throw a small silk net over their prey.

Wolf spiders

Wolf spiders are ground-hunting spiders. They do not use webs to catch prey. They run across soil, leaf litter and open ground looking for insects and other small animals.

Female wolf spiders carry their egg sac attached to their spinnerets. After hatching, the spiderlings may ride on the mother’s back for a short time.

Wolf spiders are fast ground hunters.

Jumping spiders

Jumping spiders are small, active hunters with large front eyes. They use their excellent eyesight to stalk prey, then leap onto insects from leaves, bark, rocks or walls.

Many jumping spiders are colourful. Some male peacock spiders have bright colours and perform courtship displays.

Jumping spiders have large front eyes and excellent vision.

Huntsman spiders

Huntsman spiders have long legs and flattened bodies. Many shelter under bark, in tree hollows, under rocks or in buildings. They do not build webs to catch prey.

Huntsman spiders usually run away when disturbed. They help control insects such as cockroaches, moths and flies.

Huntsman spiders have flat bodies that help them hide under loose bark.

Black house spiders

Black house spiders build messy, lacy webs in bark cracks, logs, rock crevices, walls and window frames. In bushland, they often live on rough-barked trees.

Their webs catch insects that land on or walk across the web surface.

Black house spiders build lacy webs in sheltered cracks.

Flower spiders

Flower spiders are small ambush spiders that are often found on flowers, leaves and shrubs. They usually sit still and wait for insects to come close.

Some flower spiders can blend in with petals, leaves or stems. They use their strong front legs to grab flies, bees and other small insects that visit flowers.

Flower spiders wait on flowers and leaves to catch visiting insects.

Sydney funnel-web spiders

Sydney funnel-web spiders and related funnel-web spiders live in silk-lined burrows in moist sheltered places, including some bushland and garden habitats. Their burrows may have silk trip-lines around the entrance.

Funnel-web spiders should never be handled. If a large dark spider is found, leave it alone and tell an adult.

Sydney funnel-web spiders should never be touched or handled.

Related fact sheets

More invertebrate fact sheets

• Invertebrate fact sheets – overview
• Arachnids fact sheet – learn about the animal group that includes spiders, mites, ticks and scorpions.
• Wolf spider fact sheet – learn about fast ground-hunting spiders that live in leaf litter and soil.
• Golden orb-weaving spider fact sheet – learn about large web-building spiders found in Sydney bushland and gardens.
• Net-casting spider fact sheet – learn about spiders that catch prey with a small silk net.
• Black house spider fact sheet – learn about common web-building spiders found on bark, logs and buildings.
• Sydney funnel-web spider fact sheet – learn about a medically important spider from the Sydney region.

Habitats and ecosystems

• Leaf litter habitat fact sheet – discover the habitat used by many ground-hunting spiders and small invertebrates.
• Tree habitats fact sheet – learn how bark, trunks, branches and hollows provide shelter for spiders and other animals.
• Eucalypt forest fact sheet – learn about the bushland environment that supports many Sydney spiders.
• Water habitats fact sheet – learn about creek and wetland edges where spiders such as silver orb-weavers may be found.
• Field of Mars Reserve fact sheet – learn about the reserve and the habitats found there.

Learn with us