Sydney funnel-web antivenom developed in 1981 has prevented every recorded death since — zero fatalities in 40+ years.
AgencyAustralian Reptile ParkShare →
Sydney Funnel-Web Spider
Atrax robustus
Sydney's only deadly spider. Venom kills humans but barely affects dogs. Antivenom has stopped every death since 1981.
Curated and rated by Sheriff Six-Legs and The Wild Pest field team · Six Legs Score™ (88/100, Outlaw tier) · Published Apr 25, 2026 · Updated Apr 28, 2026 · Released CC BY 4.0
88Six Legs
Six Legs Score™
88 / 100
One of the only spiders whose venom is FATAL to adult humans without antivenom — but the venom is bizarrely harmless to most other mammals. Found exclusively in a 100 km radius around Sydney, Australia. Antivenom (developed 1981) has prevented every documented death since. One of the most studied venom systems in toxinology.
Size
Body 3-5 cm; leg span 5-8 cm
Lifespan
Females up to 20 years; males 1-2 years after maturity
Range
Sydney metropolitan area, Australia (~100 km radius)
Diet
Insects, lizards, small frogs
Found in
Sheltered moist sites: under logs, in rock crevices, in suburban garages
Field guide
Atrax robustus inhabits a tightly bounded geographic range — essentially a 100 km radius around Sydney, Australia. Within that range, she is one of the most lethal spiders on Earth. The venom contains delta-atracotoxin, a peptide that triggers massive neurotransmitter release in primates and humans, causing rapid neuromuscular failure. Untreated bites can be fatal within 15 minutes to 6 hours. The toxicology is bizarre: while the venom is acutely lethal to humans, monkeys, and a few other primates, it has minimal effect on most other mammals — dogs, cats, and rodents tolerate the bite well. The reason is that delta-atracotoxin specifically targets sodium channels expressed in primate nervous systems. Antivenom developed by the CSL in 1981 has prevented every documented death from this species since (zero fatalities, hundreds of bites). Females spend their entire 20-year lives in funnel-web burrows. Males roam during summer mating season — most bites occur when males wander into garages and shoes.
5 wild facts on file
Funnel-web venom is fatal to humans and primates but barely affects dogs, cats, or rodents — it's a primate-specific neurotoxin.
JournalToxicon journalShare →
Sydney funnel-webs only exist in a 100 km radius around Sydney — one of the smallest known ranges of any deadly spider.
MuseumAustralian MuseumShare →
Most funnel-web bites are from wandering males during summer mating season — females spend their 20-year lives in burrows.
MuseumAustralian MuseumShare →
Untreated funnel-web bites can be fatal in 15 minutes — the fastest spider venom on record for human mortality.
JournalMedical Journal of AustraliaShare →
Cultural file
The Sydney funnel-web is Australia's most-feared arthropod and a centerpiece of Sydney public-health education. The Australian Reptile Park runs a citizen 'venom milking' program — locals are encouraged to safely capture funnel-webs for antivenom production. Each adult spider produces about 2-3 mg of venom, and 70 spiders are needed to produce one vial of antivenom.
Sources
AgencyAustralian Reptile Park — Funnel-WebJournalMedical Journal of Australia
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