Australian Museum: Ramon Mascord
)What do you think of when you hear the name "funnel-web spider"? Perhaps a spider that builds a funnel in its web?
On that count, then, you might think this web on a door frame is a funnel-web's home.
ABC Science: Anna Salleh
)But according to spider expert Helen Smith from the Australian Museum, funnel-webs are not likely to build on door frames.
Their webs also have a different design, with characteristic "trip lines" to alert the spider to passing prey.
The door frame web was, in fact, built by a black house spider, which doesn't have the deadly venom of an Australian funnel-web.
Dr Smith says a lot of people think they have dangerous funnel-webs in their homes when they don't and online searches can be misleading.
"There's a group of species in the northern hemisphere called 'funnel-webs' and they have a similar-looking web to the black house spider," she said.
Looks are everything
Australian Museum: Mike Gray
)There are 35 named species of Australian funnel-web spiders (that can be in the genus Atrax, Hadronyche or Illawarra).
These are in a group that includes trapdoor spiders, wishbone spiders and mouse spiders, all of which are commonly mistaken for funnel-webs.
But while mouse spiders can be as dangerous as funnel-webs, trapdoor and wishbone spiders are relatively harmless.
A key feature of funnel-webs and mouse spiders is that they are glossy on the front part of their body, where their legs are attached.
This helps distinguish them from dark-coloured trapdoor, wishbone and black house spiders, which are covered in fine hairs.
The other feature to look at are the fangs.
Black house spiders have more delicate nipping fangs that pinch sideways, while funnel-web, wishbone, mouse and trapdoor spiders have "stabbing fangs" protruding from big fang bases.
So, Dr Smith has this rule of thumb.
Australian Museum: Sue Lindsay
)If you think you might have a funnel-web, catch the spider in a jar (using instructions given by authorities) and have a closer look at it.
If it has an obvious spur or lump on the second leg from the front, it's a male funnel-web. If you see a spur on its first leg, it's a male trapdoor or wishbone spider.
(By the way, when counting legs, ignore the shorter structures at the front. These are "pedipalps" that, in the male, are involved in transferring sperm.)
And if you do indeed find a male funnel-web in the Sydney region, take it to an official drop-off site so it can be used for making antivenom.
Australian Museum: Mike Gray
)What about hole-dwellers?
You're more likely to encounter funnel-webs if you have a bushy garden, and people commonly think they have funnel-webs when they see holes in their backyard, Dr Smith said.
If these are out in the open, they're not likely to be funnel-web burrows. Funnel-webs need moisture and are more likely to burrow under a rock, step or log, or on a tree stump or even a tree.
A random hole in the middle of your lawn is more likely to belong to a trapdoor or a wolf spider, although it could be just where a cicada emerged.
Dr Smith said native spiders play a big role in keeping insects, including cockroaches and flying termites, under control and should generally be left alone.
"In general, people who respect spiders but are informed will be less stressed by many everyday situations because they are better able to appreciate when something is a real threat," she said.
Drenching the house and garden in pesticides to kill spiders may risk exposing other native animals to unnecessary poisons, she added.
Besides, sprays may not even kill burrow-living species unless you find every hole and treat them individually.
To reduce risk from spiders, Dr Smith recommends you:
- block gaps under outside doors and screens so spiders don't wander into the house
- avoid leaving things like shoes or clothes outside
- check inside and under items that are left on the ground or against walls
- don't put fingers anywhere you can't see them when picking up objects outside
- make sure children know not to touch spiders and to immediately tell an adult if they see a big blackish one
- don't go out at night without shoes and a torch
- learn first aid and make sure to keep a compression bandage available
- beware apparently dead spiders at the bottom of a swimming pool — funnel-webs can survive quite a while under water.
