Head to head
Funnel-web Spider vs Redback Spider
The Sydney funnel-web and the redback are the two spiders Australians are taught to take seriously, and both have their own antivenom. They are very different animals, and the danger they pose differs in speed, severity, and who gets bitten.
| Funnel-web Spider | Redback Spider | |
|---|---|---|
| Group | Mygalomorph (tarantula branch), family Atracidae | Widow spider, genus Latrodectus |
| Size | Body 1 to 5 cm, stout | Female body ~1 cm; male tiny |
| Where it lives | Silk-lined burrow in the ground | Untidy web in a sheltered nook |
| Who bites | Mainly wandering males | Only the female |
| Venom speed | Fast; emergency within 1 to 2 hours | Slow; pain builds over hours |
| Danger | Potentially fatal untreated | Very painful, rarely life-threatening |
| Deaths since antivenom | None since 1981 | None since 1956 |
| First aid | Pressure immobilisation bandage, hospital | Ice and pain relief; no pressure bandage |
Funnel-web Spider vs Redback Spider: common questions
Which is more dangerous, a funnel-web or a redback?
The funnel-web is the more acutely dangerous. A serious bite from a male Sydney funnel-web is a medical emergency that, untreated, can kill a person within a few hours, and it was responsible for at least 13 deaths before its antivenom was introduced in 1981. A redback bite is very painful and can make someone quite ill over a day or two, with spreading pain, sweating, and nausea, but it is rarely life-threatening and there have been no confirmed redback deaths since 1956. In practice, redbacks cause many more bites because they are common around houses, but funnel-web bites are the ones treated as immediately life-threatening.
What first aid is different for the two spiders?
For a suspected funnel-web bite, apply the pressure immobilisation technique at once: firmly bandage the whole bitten limb and splint it to keep it still, exactly as for a snakebite, because the venom spreads through the lymphatic system and movement speeds it up. Then get to a hospital urgently. For a redback bite, pressure immobilisation is not recommended, because the venom acts slowly and localising it can make the local pain worse; instead, apply an ice pack for the pain, take simple pain relief, and seek medical advice, with antivenom reserved for severe or worsening cases. Getting the identification right matters, so if the spider can be safely contained, bring it.
Are these spiders related to spiders elsewhere in the world?
The redback is, closely. It is a member of the widow genus Latrodectus, the same group as the North American black widows, the European and Mediterranean widows, and the South African button spiders, and their venoms and bites are all broadly similar. The Australian funnel-webs are more isolated: they are mygalomorph spiders, related to tarantulas and trapdoor spiders, and while there are funnel-web-like mygalomorphs elsewhere, the dangerously venomous family Atracidae is found only in Australia. The common funnel-weaver spiders of gardens in North America and Europe are unrelated harmless spiders that happen to share the funnel-web name.