Habitat: Trapdoor spiders dig burrows in the ground with their fangs. The fangs are mounted on mobile “turrets” that contain poison glands. Each turret has a comb of spines on its underside. The spider uses the comb to sweep soil into pellets that it dumps outside. A hinged lid, or trapdoor, fits neatly in the mouth of the burrow. Some are thin flaps, but most are thick slabs made of silk and soil. The spider chisels the edges of the lid with its fangs to get an exact fit. It attaches it with a silk hinge and covers the top with plant debris. The result is a perfectly camouflaged retreat. It provides protection against the weather and most predators and is an ideal lair from which to pounce.

Food and Hunting: The hunting methods of trapdoor spiders vary according to habitat. Species living in moist places with plenty of insects can rely on the ambush. At night the spider lurks at the entrance to its burrow. It puts out its front two pairs of legs, which have hairs that are sensitive to ground vibrations. When a victim passes by, the spider lunges forward and strikes. Some trapdoor spiders live in drier habitats, where there are fewer insects. These species have better eyesight and longer legs. They often pursue their quarry for some distance from the burrow.

Some species lay traps for their prey. They stretch silken trip wires from the burrow or even small twigs wired with silk. At the slightest twitch, the spider rushes out and plunges its fangs into the victim. The venom kills the prey in seconds and begins to digest its tissues, making a soup the spider can suck up at leisure. The trapdoor spider stays half inside the burrow as it waits for prey to pass by.

Enemies: Despite their well defended homes, trapdoor spiders are vulnerable to spider hunting wasps. The wasp can flip back the trapdoor, dive in, and paralyze the spider with a sting. Some spiders cling to the trapdoors, but the wasp simply slices through the door with its shearing jaws. The wasp then lays an egg. When it hatches, the wasp grub eats the spider. Some species strengthen their defenses. Several species build complex burrows with side chambers and extra doors. An Australian species digs a Y shaped burrow with an escape tunnel. When in danger, the trapdoor spider adopts a threat posture and displays its fangs.

Breeding: For the male spider, mating can be hazardous. The female, which is usually larger, may not recognize him as a suitor. Conditioned by her predatory instincts, she is likely to regard him as a meal. Females rarely stray far from their burrows. The male is guided by a pheromone (a special chemical attractant) that the female releases and by the distinguishing pattern of silk around her burrow. Some males perform courtship dances. They drum their legs in a way that seems to lull the female into a state of receptiveness. Then the male impregnates her with a drop of sperm from a capsule on the end of his palp (feeler). The eggs are laid in the burrow, in a cocoon attached to the silk lining. The hatchlings look like miniature versions of their mother and stay with her for several weeks. The female trapdoor spider seldom ventures far from her well camouflaged burrow.

Key Facts:
Sizes:
Length: About 1 in.
Mouthparts: Pair of downward pointing poison fangs for piercing, crushing, and digging
Eyes: 4 pairs of simple eyes

Breeding:
Breeding season: Summer in temperate regions; year round in the tropics
Eggs: Laid in burrow. Number varies according to species

Lifestyle:
Habit: Stays in burrow by day and ambushes prey from burrow by night
Diet: Ground dwelling insects and other invertebrates
Lifespan: Normally 1-2 years
Related Species: Include the European purse web spider, Atypus affinis, and the funnel web spider, Atrax robustus.
Distribution: Various species are found throughout the world, in the warm climates of tropical, subtropical, and warm temperate regions.
Conservation: Some species of trapdoor spider are quite rare because of their very localized distribution, but no species is known to be endangered.

Burrows of Trapdoor Spiders: Trapdoor spiders use their burrows to conceal themselves when hunting prey. The burrows also serve as protection against enemies and as nests in which to raise young.
Burrow: Built in a variety of shapes. The simplest is a tubelike tunnel. It may be up to 1 foot deep and 1½ inches in diameter.
Hunting: The spider waits for its prey at the mouth of the burrow. It stays half hidden beneath the trapdoor.
Prey: When an insect passes by, the spider opens the door, seizes and poisons its prey, and drags it into the burrow.

Did You Know: A female trapdoor spider may spend her whole life inside her burrow, enlarging it as she grows.
Trapdoor spiders can move up to 140 times their own weight.
In arid areas trapdoor spiders often build burrows under a tree to snare insects attracted to the tree’s moisture.
Some Australian trapdoor spiders build walls around burrow entrances as protection against flooding.
The spider strikes so quickly that it occasionally drags inedible prey into its burrow by mistake

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