[1] Some members of the family produce venom that is dangerous to humans, and bites by spiders of six of the species have caused severe injuries to victims.

[6] Australian funnel-web spiders make their burrows in moist, cool, sheltered habitats – under rocks, in and under rotting logs, and some in rough-barked trees (occasionally meters above ground).

In 1901, Henry R. Hogg considered them to be sufficiently distinctive to form a separate group, which he called "Atraceae"[9] – the basis of the modern family name Atracidae.

[11] Dipluridae Hexathelidae Porrhothelidae Macrothelidae Calisoga (Nemesiidae) Hebestatis (Halonoproctidae) Atracidae Actinopodidae As of April 2019[update], the World Spider Catalog accepts the following genera:[12]

Adult males, recognised by the modified terminal segment of the palp, tend to wander during the warmer months of the year, looking for receptive females for mating.

[citation needed] The volume of venom delivered to large animals is often small, possibly due to the angle of the fangs, which are not horizontally opposed, and because contact is often brief before the spider is brushed off.

[18] One member of the genus Hadronyche, the northern tree-dwelling funnel-web spider, has also been claimed to cause fatal envenomation,[7] but to date, this lacks the support of a specific medical report.

In 2021 researchers from the University of Queensland announced that the venom from funnel-web spiders found on Fraser Island contains the molecule Hi1a that could block the cell death message after a heart attack, protecting the heart after major injury and potentially preventing or minimising muscle damage.

[18] These toxins are thought to induce spontaneous, repetitive firing and prolongation of action potentials, resulting in continuous acetylcholine neurotransmitter release from somatic and autonomic presynaptic nerve endings.

This in turn inhibits neurally mediated transmitter release, resulting in a surge of endogenous acetylcholine, noradrenaline, and adrenaline.

As systemic envenomation progresses, symptoms include nausea, vomiting, shortness of breath (caused by airway obstruction), agitation, confusion, writhing, grimacing, muscle spasms, pulmonary oedema (of neurogenic or hypertensive origin), metabolic acidosis, and extreme hypertension.

The final stages of severe envenomation include dilation of the pupils (often fixed), uncontrolled generalised muscle twitching, unconsciousness, elevated intracranial pressure, and death.

Death generally is a result of progressive hypotension or possibly elevated intracranial pressure consequent on cerebral oedema.

First-aid[26] treatment for a suspected Australian funnel-web spider bite consists of immediately applying a pressure immobilization[27] bandage; a technique which consists of wrapping the bitten limb with a crepe bandage, as well as applying a splint to limit movement of the limb.

This technique was originally developed for snakebites, but has also been shown to be effective at slowing venom movement and preventing systemic envenomation in case of an Australian funnel-web spider bite.

[31] The purified rabbit IgG antivenom was developed in 1981 through a team effort led by Dr. Struan Sutherland, head of immunology at the Australian Commonwealth Serum Laboratories in Melbourne.

[33] Antivenom therapy has shortened the course of envenomation effects; prior to its availability, the average length of hospital treatment for severe bites was about 14 days.