Trapdoor spider fact sheet | Field of Mars EEC

What are trapdoor spiders?

Trapdoor spiders are ground-dwelling spiders that spend much of their life in silk-lined burrows. Many are brown, stocky spiders with short, blunt spinnerets at the end of the abdomen.

Trapdoor spiders belong to a spider group called mygalomorphs. This group also includes funnel-web spiders, mouse spiders and tarantulas. Mygalomorph spiders usually have strong bodies and fangs that move downwards rather than sideways.

The name trapdoor spider can be misleading. Some trapdoor spiders build a hinged door over their burrow, but many species have an open burrow with a silken rim instead. In Sydney, one local example is the Sydney Brown Trapdoor Spider, Arbanitis villosus.

A trapdoor spider.

Trapdoor spiders live in burrows.

Where do trapdoor spiders live?

Trapdoor spiders live in burrows in the ground. Their burrows may be found in bushland, gardens, lawns, open forest, soil banks and other places where the soil can be dug and the entrance can be hidden.

The Sydney Brown Trapdoor Spider is found in lawns, gardens and bushland around the Sydney region. Other trapdoor spider species also occur in the Sydney area, so it can be difficult to identify them to species level without expert help.

A trapdoor spider burrow is usually lined with silk. Some burrows have a camouflaged door made from soil, silk and plant material. Other burrows are open, with a silken rim attached to grass, leaf litter or soil.

This trapdoor spider burrow has been extracted from soil. How long is it?

The door of a trapdoor spider burrow can be difficult to see because it is covered with soil, lichen and moss.

What do trapdoor spiders eat?

Trapdoor spiders are carnivores. They eat other small animals, especially ground-dwelling invertebrates such as crickets, beetles, cockroaches, slaters, spiders and moths that come close to the burrow entrance.

Trapdoor spiders do not build aerial webs to catch flying insects. Instead, they are ambush predators. They wait near the entrance of the burrow and rush out when prey comes close enough to grab.

This hunting style helps trapdoor spiders save energy. They can stay hidden and protected while waiting for food to pass nearby.

Trapdoor spiders are ambush predators that wait near the entrance of their burrow for prey to come close.

What is the life cycle of a trapdoor spider?

Trapdoor spiders hatch from eggs inside the female’s burrow. The young spiderlings stay in the burrow for a time before dispersing on the ground and building their own small burrows.

Females often stay in or near their burrows for most of their lives. As a female grows, she widens the burrow. In species that build doors, the spider may add new material around the door as the burrow becomes larger.

Adult males leave their burrows to search for females. Mating usually takes place inside the female’s burrow. If the male survives, he may mate with more than one female before dying.

Trapdoor spiders can live for many years. Some species live between 5 and 20 years. The longest-lived spider ever recorded was a female trapdoor spider from Western Australia known as Number 16. She was at least 43 years old.

Deep burrows are a safe place for trapdoor spider eggs to hatch.

What adaptations do trapdoor spiders have to help them survive?

Trapdoor spiders have several adaptations that help them survive underground. Their strong bodies and legs help them dig and move through soil. Their silk-lined burrows help protect them from drying out, predators and changes in temperature.

Their colour helps them blend in with soil, bark and leaf litter. In species that make doors, the burrow entrance can be covered with soil and plant material, making it very difficult to see.

Trapdoor spiders are also well adapted for ambush hunting. They can wait safely inside the burrow until prey comes close, then rush out quickly and grab it with their strong mouthparts.

Trapdoor spiders hide in their burrows to avoid predators and wait for prey.

Why are trapdoor spiders important?

Trapdoor spiders are important predators in gardens and bushland. They help control numbers of ground-dwelling invertebrates, including beetles, crickets, cockroaches and other small animals.

They are also part of the food web. Birds, bandicoots, centipedes, scorpions, parasitic wasps and some flies may feed on trapdoor spiders or their young.

Trapdoor spiders also show why soil and leaf litter habitats are important. A small hole in the ground may be the entrance to a long-lasting home used by a spider for many years.

Ground-dwelling insects living in leaf litter are part of trapdoor spider food webs.

How can you help trapdoor spiders?

You can help trapdoor spiders by protecting soil, leaf litter and natural ground habitat. Avoid digging up burrows or poking sticks into holes, as a burrow may contain a spider, eggs or young spiderlings.

Leave leaf litter, logs and natural ground cover in bushland areas where it is safe to do so. These materials help protect small animals and support the invertebrates that trapdoor spiders eat.

If you find a large dark spider, observe it from a safe distance. Trapdoor spiders are often confused with funnel-web spiders and mouse spiders, so do not handle them. If a spider is inside a building and needs to be moved, ask an adult for help and use safe spider removal advice.

Protecting natural areas is one of the best ways to provide habitat for trapdoor spiders and other animals.

Related fact sheets

More invertebrate fact sheets

• Invertebrate fact sheets – Explore more animals without backbones, including insects, spiders, worms and other small animals.
• Arachnids fact sheet – Learn how spiders fit into the arachnid group and how arachnids differ from insects.
• Spider fact sheet – Learn about spider body parts, silk, prey, safety and different spider groups.
• Sydney funnel-web spider fact sheet – Compare another ground-dwelling mygalomorph spider from the Sydney region.
• Huntsman spider fact sheet – Compare trapdoor spiders with large active hunting spiders that do not live in burrows.

Habitats and ecosystems

• Leaf litter habitats fact sheet – Explore the ground layer where many spiders, insects and other small animals shelter.
• Rock and log habitats fact sheet – Learn how rocks, logs and sheltered ground spaces support invertebrates.
• Ground cover habitats fact sheet – Find out how low plants protect soil and shelter small animals.
• Eucalypt forest fact sheet – Explore the local bushland ecosystem that supports many spiders and other invertebrates.
• Field of Mars Reserve fact sheet – Discover the local reserve habitats that support spiders, insects and other wildlife.

Food webs and ecological relationships

• Wasp fact sheet – Learn about wasps, including spider wasps that hunt spiders to feed their young.
• Centipede fact sheet – Compare another leaf-litter predator that hunts small animals under rocks, logs and bark.

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