Are Funnel Web Spiders Poisonous? Unraveling the Truth

Funnel web spiders are known for their distinct web shapes and potential to deliver venomous bites.

There are over 40 species of these spiders, but one particular species, Atrax robustus or Sydney funnel-web spider, is responsible for most human fatalities in Australia.

These spiders have medium to large body sizes and are typically dark-colored, ranging from black to brown.

While their venom can be harmful to humans, it’s important to note that not all species carry the same level of toxicity.

For example, male funnel-web spider bites are generally considered more toxic than bites by female spiders.

Funnel Web Spider Overview

Brief History

Funnel web spiders are known for their distinctive webs and their venomous bite. They first gained attention in the 1920s when their venom was discovered to be toxic to humans, especially in the case of the Sydney funnel-web spider.

Different Species

There are over 40 species of funnel-web spiders, with some of the most dangerous being found in Australia, such as the Atrax robustus, otherwise known as the Sydney funnel-web spider.

Other non-lethal species can be found in Europe and New Zealand.

Some characteristics of funnel-web spiders include:

• Medium to large size
• The gray or brown coloration
• Tendency to create funnel-shaped webs

Habitat and Distribution

Funnel-web spiders are native to various regions, including:

• Eastern Australia (Sydney funnel-web spider)
• Europe
• New Zealand

These spiders typically build their webs in habitats such as:

• Forests
• Gardens
• Shrublands

Funnel-web spiders vs other spiders

Feature	Funnel-web Spiders	Other Spiders
Venom	Potentially toxic	Mostly Harmless
Type of web	Funnel-shaped	Varies
Habitat	Forests, gardens, etc	Wide range
Geographic region	Aust., Eur., NZ	Worldwide

Venom and Bites

Venom Toxicity

Funnel web spiders, particularly the Atrax robustus, are known for their venomous bites. The venom contains neurotoxins that can severely affect the nervous system. For comparison, consider these two types of spiders:

Spider	Venom	Danger Level
Sydney Funnel-web	Atrax robustus	Highly toxic
Tegenaria/Eratigena	Lesser toxic	Rarely dangerous

Symptoms and Presentation of Bites

Funnel-web spider bites can cause various symptoms, such as:

• Sensory disturbances
• Muscle paralysis
• Increased heart rate
• Elevated blood pressure

The presentation of bites may differ between victims, but these are common indicators.

Lethal Envenomation Syndrome

In severe cases, envenomation can lead to a condition called Lethal Envenomation Syndrome. It involves:

• Rapid onset of symptoms
• Potential fatalities in high-risk victims

Atrax robustus is known to cause the most human fatalities among Australian spiders.

Treatment and Antivenom

Successful management of funnel-web spider bites includes:

• Timely evaluation
• Prompt administration of antivenom

Integrated healthcare strategies can improve coordination and communication between healthcare providers to handle spider bite cases.

Anatomy and Life Cycle

Physical Characteristics

Funnel web spiders are medium-sized arachnids, exhibiting unique features. Their body size ranges from 6 to 11.5 millimeters depending on gender and species.

These spiders have a dark-colored abdomen with lighter markings on the back, red-brown cephalothorax, and a covering of pale-yellow hairs.

Notable characteristics:

• Sharp fangs capable of penetrating soft shoes and fingernails
• Hairy body
• Iridescent metallic-colored abdomen in some species

Reproduction and Mating Practices

Funnel-web spiders typically have brief mating encounters, mostly during the warmer months.

Female funnel web spiders produce egg sacs containing hundreds of eggs, which they guard diligently in their nests until the spiderlings hatch.

Nest Building

Funnel web spiders are known for their unique web structures which have a silk entrance resembling a funnel shape, leading to the spider’s burrow ⁴. Inside the tunnel, the spider waits to capture its prey by sensing vibrations in the web.

Development and Growth

After the spiderlings hatch from the egg sac, they undergo several molts to reach adulthood. The growth process differs across various species within the funnel-web spider group, including the Illawarra and Hadronyche genera ⁵.

Here’s a comparison table of some physical features between two Australian funnel-web spider species:

Feature	Atrax robustus	Hadronyche illawarra
Size (mm)	7.5 – 11.5	6 – 9
Color	Red-brown	Brown
Silk Structure	Funnel-shape	Funnel-shape
Venom	Highly toxic	Less toxic

Prevention and Safety Measures

Inspecting your Environment

To prevent funnel web spider encounters, regularly inspect your surroundings. Funnel web spiders often dwell in natural spaces like logs and tree bark. Before settling in, examine these areas for any spider activities.

Here are some key environmental elements to check:

• Logs
• Rocks
• Tree barks
• Shrubs

Keep in mind that disturbing a spider habitat could lead to bites, so exercise caution when inspecting. If possible, use tools to help examine and move around physical obstacles.

Maintain a clear line of sight, and use good lighting to avoid any unpleasant surprises.

Use of Protective Clothing and Footwear

Wearing appropriate attire minimizes potential harm from spider bites. Opt for long-sleeved shirts, gloves, and hats when handling materials or working near potential spider habitats.

Protective footwear such as closed-toed shoes is essential, as funnel web spiders possess powerful fangs, capable of penetrating soft shoes.

By investing in protective gear, you can reduce the risk of bites from dangerous spiders like the male funnel-web spider, brown recluse spider, and hobo spider.

What to Do if You Encounter a Funnel Web Spider

If you come across a funnel web spider, remain calm and avoid making any hasty movements. Here are some steps to take:

1. Slowly back away, maintaining a safe distance.
2. Observe the spider to assess if it’s threatening or passive.
3. Do not attempt to capture or kill the spider if it poses no immediate danger.

Understand these prevention measures and have an action plan in case of an encounter with a dangerous spider.

Remember that calmness and awareness are key to avoiding undesired interactions with these potentially venomous arachnids.

Preventive Measures

Inspect your environment: Regularly check logs, rocks, tree barks, and shrubs for spider activity.

Wear protective clothing: Long sleeves, gloves, hats, and closed-toed shoes can minimize bite risk.

Remain calm in encounters: Back away, observe, and avoid provoking a funnel web spider.

By adhering to these guidelines, both adults and children can take necessary precautions to prevent encounters with dangerous spiders and ensure their safety.

Other Funnel Web Spiders

Brown Recluse Spider

The Brown Recluse Spider, native to the United States, is known for its venomous bite. Although not a funnel web spider, it is still worth mentioning due to its potential danger to humans. Some features include:

• Violin-shaped markings on the body
• Six eyes (rather than the usual eight for spiders)

Bite symptoms can range from mild to severe, including:

• Redness and swelling
• Intense pain hours after the bite
• Skin necrosis in severe cases

Hobo Spider

The Hobo Spider, found primarily in the Pacific Northwest, is a funnel web spider known for its aggressive behavior. Characteristics include:

• Brown coloration with chevron patterns on the abdomen
• Larger than other funnel web spiders

While previously thought to be dangerous to humans, recent studies suggest their venom may not be as harmful as once believed.

The Tegenaria and Eratigena Genera

The Tegenaria and Eratigena genera consist of various funnel web spiders, most notably the Giant House Spider and the Barn Funnel Weaver.

These spiders are relatively harmless to humans and are often found in residential areas. Features include:

• Large, hairy legs
• Fast runners

A comparison of the spiders mentioned:

Spider	Funnel Web	Venomous	Common Location
Brown Recluse	No	Yes	United States
Hobo Spider	Yes	Yes*	Pacific Northwest
Giant House Spider	Yes	No	Europe, North America
Barn Funnel Weaver	Yes	No	North America, Europe

Funnel Web Spider Behavior and Prey Capture

Nocturnal Activity Patterns

Funnel web spiders are generally nocturnal creatures. They are most active during the night, while they usually remain hidden during the day. Here are some common nighttime activities of these spiders:

• Hunting for prey
• Mating
• Wandering in search of a mate

Prey Detection and Capture

Funnel web spiders have a unique method for detecting and capturing their prey. They use their eight eyes, which are arranged in two rows and located on the cephalothorax.

These spiders are sensitive to vibrations they sense through their webs. When an insect lands on the web, the spider quickly reacts to the vibrations and comes out of its burrow to capture the prey.

The Role of Funnel-Shaped Webs and Silk

Funnel-shaped webs play a vital role in the life of funnel web spiders. They are designed not only for capturing prey but also for providing shelter and hiding spots.

Here are a few noteworthy features of these webs and the silk used to create them:

• Funnel-Shaped Webs: These webs have a flat sheet-like structure with a funnel-shaped retreat leading to a hidden burrow or crevice.
• Trap Prey: Insects that walk or fly onto the web are trapped, allowing the spider to capture them.
• Agelenidae and Dipluridae: Funnel web spiders belong to these two families, which include grass spiders and medium-sized spiders.
• Silk: Funnel web spiders produce silk that is both strong and flexible, allowing them to construct sturdy webs for hunting and protection.

Characteristics of Funnel Web Spiders

• Medium-sized
• Dark-colored, ranging from black to brown
• Eight eyes arranged in two rows
• Funnel-shaped webs for capturing prey
• Females produce egg sacs for reproduction

Comparison of Funnel Web Spiders and Grass Spiders

Feature	Funnel Web Spiders	Grass Spiders
Web Shape	Funnel-shaped web with a hidden retreat	Sheet-like web with a downward funnel
Families	Agelenidae and Dipluridae	Agelenidae
Prey	Insects trapped in the web	Insects trapped in the web, mostly ground-dwelling

Health Impacts and Management

Physical Reactions to Bites

Funnel web spiders are known for their powerful, sharp fangs that can even penetrate fingernails and soft shoes. Envenomation induced by their venom can cause a variety of symptoms.

• Local: Pain, swelling, and redness
• Muscle spasms: Involuntary muscle contractions
• Respiratory distress: Difficulty breathing

Nausea, Vomiting, and Drooling

The venom of funnel-web spiders contains neurotoxins that stimulate neurotransmitter release, leading to a range of symptoms like nausea, vomiting, and excessive drooling.

Long-Term Effects

Proper management of funnel-web spider bites, such as prompt transportation to the hospital, ventilatory support, and administration of antivenom, can significantly reduce the risk of long-term effects.

However, delayed or inadequate treatment can result in more severe outcomes.

Pros of prompt treatment:

• Reduced risk of long-term effects
• Faster recovery

Cons of delayed treatment:

• Increased risk of long-term effects
• Prolonged recovery period

Treatment	Pros	Cons
Prompt treatment	Reduced risk of long-term effects	–
Delayed treatment	–	Increased risk of long-term effects

To minimize the harmful effects of funnel-web spider bites, it’s crucial to seek immediate medical attention and follow proper management practices.

Conclusion

In the world of arachnids, funnel web spiders are one fascinating creature that is known for their ability to distinctive web structures. These insects are also known for their venomous bites.

In fact, species like the Sydney funnel-web spider hold a notorious reputation for its potential danger to humans. Their venom can cause a range of symptoms, from muscle paralysis to increased heart rate.

However, Thankfully, not all species are equally toxic. Bites from some species are less harmful. By the behavior of these insects, you can stay and co-exist peacefully.

Use the information given in the article to know the various threats these insects possess and how to cure them properly.

Footnotes

1. Barn Funnel Weaver Spider ↩

2. Funnel Web Spider Toxicity ↩

3. Funnel-web spider bite: MedlinePlus Medical Encyclopedia ↩

4. Predatory Spiders ↩

5. Funnel Web Spider Toxicity – StatPearls – NCBI Bookshelf ↩

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about funnel web spiders. Scroll down to have a look at some of them.

Letter 1 – Unknown Spider from Germany is Grass Spider

Spider in Germany, Deployed Husband OH MY!
Location:  Southwestern Germany
September 26, 2010, 2:57 pm
Hello! I am coming across these fabulous creatures almost daily in my home and can’t take much more. My husband is currently deployed and I can only handle so much.

We are currently stationed in Germany, and while I love it here, I can’t take these guys greeting me when I first wake up. Plus, my son and I have been experiencing bites on our faces and arms, and can’t help but wonder if these guys have something to do with it. Some are as big as my palm!

Please help so I can make it through the last 6 weeks of this 6-month deployment. I appreciate your help!
Signature:  Scared Military Spouse in Europe

Dear Scared Military Spouse,
We do not recognize your Spider, but in the interest of providing you with some information, we are posting your letter with the image of an unidentified Spider in the hopes that our readership will be able to come to your assistance.

Karl bails us out again: Unknown Spider from Germany – September 26, 2010
Hi Daniel:
I think this is probably a Funnel Weaving or Grass Spider (Agelenidae) in the genus Tegenaria. A family characteristic is eight eyes, in two rows of four, and I think I can just make out the top row in the photo.

The common English names in northern Europe for spiders in this genus include House, Giant House, Common House, and Domestic Spider (and probably more).

There are at least 12 representatives in that part of Europe and they look too similar to me to make a call, but I think it may be either T. atrica or T. domestica. The infamous Hobo Spider of western North America is in the same genus (T. agrestis) and is an accidental introduction from Europe.

Although they are all venomous, other than the Hobo Spider they don’t appear to have a reputation for biting humans (they do frighten them, however). The long-legged ones are males and they are the ones that are commonly seen wandering around homes in the fall in search of females.

Regards.  Karl

Karl is my hero! Danke!
I’d like to send some German Spider-Free Chocolate as a thank you. May I please have your mailing address?
Vielen Dank,
Anna Roser

Letter 2 – Protected, Endangered Andalucian Funnel-Web Spider found dead in Spain

Subject:  Black hairy scary spider
The geographic location of the bug:  Marbella, Spain
Date: 06/03/2021
Time: 11:30 AM EDT
Your letter to the Bugman:  Could you please help me to identify this spider? It is dead, but I think pretty recently as I used a pencil to extend its front leg and it didn’t break.

I thought it was going to move. Found it on the living room floor. Size is about 1″ body length, front leg 1-1/4″ long. Approximately, didn’t have time to measure it. Is it poisonous, or deadly?

Live in Southern Spain, Costa del Sol, less than 1 mile from the Mediterranean Sea. Any info can help. Do you think a family is nearby?
How you want your letter signed:  Debi

Dear Debi,
The extremely long spinnerets on the tip of the abdomen are such a distinguishing feature, we had no trouble identifying the endangered Andalucian Funnel-Web Spider, Macrothele calpeiana, on The Olive Press where it states: 

“The Andalucian funnel-web spider is considered to be the largest in Europe and is easily recognizable.  They are jet black with a glossy carapace and fine hairs on their legs and abdomen.  The 1.5 cm-long spinnerets, at the rear, almost look like extra legs. The body can be up to 3.5 cm long and the stretched legs can reach a span of 8 cm.” 

The site also states:  “This is the only spider in Europe to be protected by the European Union Habitats Directive.  They are found mostly in Cádiz and Málaga provinces with smaller numbers in scattered enclaves discovered in Huelva, Sevilla, Granada, Jaén, Gibraltar, and the furthest north Badajoz, in Extremadura.” 

According to Wildside Holidays (where those prior two quotes appear to have originated):  “These spiders are most active at night when they will wait at the tunnel entrance for prey to become glued onto the silken web.

Their diet consists of small insects such as beetles, woodlouse, millipedes, and crickets. When they feel the vibration of a trapped insect they will carefully approach, then bite the ill-fated prey with venom which will begin to liquefy it as they wrap it in silk.

The venom is injected into their prey through openings in the tips of the pair of fangs. The glands that produce this venom are located in the two segments of the chelicerae. (The parts to which the fangs are attached).” 

By the way, we are relieved to learn you discovered this magnificent spider dead as we did not want to have to tag your posting as Unnecessary Carnage.

Letter 3 – Newsflash: Funnelweb Spiders in Australia

Ed. Note: We do not like to spread paranoia, but we thought in the interest of public awareness, we should post this link.

Aloha Daniel –
FYI –
A hui hou –
Eliza
http://www.independent.co.uk/news/world/australasia/killer-funnelweb-spiders-invade-sydney-1874230.html

Letter 4 – Male Grass Spider, we believe

Subject:  In the Agelenopsis genus????
The geographic location of the bug:  Canada, Ontario, Ottawa
Date: 09/23/2017
Time: 07:35 AM EDT
Hello! There’s a big spider web on my porch. I’ve been watching it grow, throwing moths in there all summer. Because of how massive the web is, it’s really hard to snap a clear picture of the spider.

However, one morning, I spotted a second spider wandering in and around the web. Looks exactly like the one who ones the web but it’s got a thinner body and longer legs.

I’m suspecting it was a male wandering for the female. Either way, I’ve made a bit of research in my identification book but can’t find a spot-on description/picture of them.

Here’s a clear picture of the suspected male and a blurry picture of the suspected female!
Thanks for everything you do, I love wandering on your website!
How you want your letter signed:  Madeleine Blais

Dear Madeleine,
Though we cannot make out the spinnerets in your image, and the spinnerets of Grass Spiders in the genus Agelenopsis are generally quite prominent, we believe you are correct that this is a male Grass Spider from that genus. Here is a BugGuide image for comparison.  

Since the female has been living in a web, that is additional evidence that this is a Grass Spider or Funnel Web Spider.  Thanks for the kind words.

Letter 5 – What’s That Spider???

*URGENT*~Brown Spider with Black Stripes~PLZ IDENTIFY~*URGENT*
Location: Columbus, Ohio, USA- near cut firewood in the backyard
September 20, 2011 12:15 am
Dear Mr. Bugman, I live in Columbus, Ohio & I just moved from the west side (Hilltop) to the north side (Easton) area. Right outside my apartment at night on the 19th of September, almost midnight I went to sit on my step to smoke since I do not smoke indoors.

I saw something kinda looked balled up but in the dark, I really couldn’t tell so I kinda scooted it off my step with my bare hand. I thought nothing of it & continued smoking my cigarette & entered back into my house.

Going out a second time to smoke, this time I turned the porch light on & right where I had kinda flicked the thing was a big, nasty-looking spider. There is a big wooden stand that holds cut firewood right on that side of my door, in the backyard.

This spider was bigger than most I have seen around here, in my house as well as from what I have ever seen around the Hilltop. So, naturally, I am looking for markings immediately.

I have been bitten by a nasty- poisonous spider before & it has left its mark on me permanently. I have the scar to this day, not a pretty memory I care to remember or even admit. So, I do have some fear.

However, I also have what I call ’population control’ around my house; which is where I determine by the size, quantity, location, & just pure looks which spider I shall allow to live on, in, & around my house.

If these spiders do not meet my standards of ’safety versus benefits’ I am sorry to say, they must die & I take them out immediately. Most of the time- a shoe, sometimes the occasional death by being flushed down the toilet or rinsed with water down the sink, shower, or bath.

Anyhow, this spider out back of my new house has me worried & I cannot quite put my finger on what type of spider it is. Before I should decide this spider’s fate, I am trying to give it the benefit of the doubt here.

I need your expertise… It is brown, slightly hairy but not too much though. It has what looks like 2 black stripes from his head down his back to the very end of him. I did notice on his (but) area, it looks as if whatever those things are, (two somethings) maybe his spinners or what he uses to make his web, but they look rather long or protruding.

I have never seen them so defined on other spiders before. They are easily recognizable on the end of the back of his body. I cannot see his face though. Just 2 black stripes from what looks like end to end.

Please, if you can help me with the identification of this, I almost want to say beast because he is so scary… but of this creature. I would greatly appreciate it. I think from the pictures I have seen, I would say he is either a ’Wolf Spider’ or a ’Grass Spider’. To me, he does not match perfectly with either.

I am concerned because of my kids. They play in this yard as well as walk-in & out of that door when needed. The difference between the two spiders I mentioned is extremely important.

From what I have gathered a ’Grass spider’ can be very poisonous. A ’Wolf Spider’ doesn’t look too pleasant either. so, if you would ever so kindly please help me, I will forever be ever grateful to your cause & your generosity. thank you kindly, with love from The Hall Family……Sincerely, Lilly Hall

ps. It is the beginning of Fall here & it did just rain today. When I went back outside to see if I could get better-quality pictures. I went to take a picture of the web it spun in between the wood logs & discovered another one already.

Now, I’m freaked out there is a whole family out there. Also, I caught a slug, worm & God only knows what else all these bugs are- coming from underneath my step. It’s like a jungle out there. AHHHH, somebody helps me.

Then I remembered it did rain…. I sure hope the pics are good enough to help u identify the species. I took it from my 3.0 megapixel Samsung Rogue cell phone. You can always zoom in on it, especially if u have some good software. I am sorry I didn’t have a better camera. thanks for listening.

Plz, email me back, thx so much….

Signature: Authentically, I’m not sure I understand. Please, by any means you wish. whichever way is best I would guess. thank you. sorry I do not understand what this is asking….

Dear Authentically, I’m not sure I understand. Please, by any means you wish. whichever way is best I would guess. thank you. sorry I do not understand what this is asking….,
Our staff is speechless.  If the spider spun a web that looked like a funnel with a retreat hole, then it is most likely a Funnel Web Spider, a family that includes the Grass Spiders in the genus Agelenopsis. 

If it hunted without a web, it is most likely a Wolf Spider.  Any Spider might bite if provoked or carelessly handled.  Some people might be allergic to the bites of certain Spiders because not all spider venom is the same. 

If you are nervous about Spiders and other bugs, we suggest you get rid of the wood pile by the house.  In our opinion, smoking is a bigger threat to your health than a spider.