Five of the World's Deadliest Spiders

1. Sydney Funnel-Web Spider

Known For: Having fangs capable of piercing a human fingernail  
Location: Australia, especially around Sydney   

The Sydney Funnel-Web Spider is one of Australia’s many nature-dwelling death machines, infamous for its potent venom and proximity to populated areas. These spiders are known for their aggressive nature and are known to deliver multiple bites when threatened (just like my cat). A single bite can deliver enough venom to cause serious symptoms within minutes, including difficulty breathing, extreme sweating, and convulsions. The neurotoxins in their venom can affect the nervous system, leading to potential respiratory failure if not treated quickly. 

Fun Fact: Between 1927 – 1979, only 14 deaths (about 1% of all recorded bites) were attributed to Funnel-Web Spiders. Zero deaths have been reported since the development of an antivenom in 1981. 

2. Brazilian Wandering Spider

Known For: Aggression and powerful venom, fondness of produce  
Location: South America, especially in the Amazon and Atlantic rainforests   

Brazilian Wandering Spiders are often considered one of the most venomous spiders in the world. These spiders are nocturnal, wandering the forest floor at night in search of prey, though they occasionally wander into homes and even shoes. Their venom can cause severe muscle pain, breathing difficulties, and sometimes fatal respiratory paralysis if left untreated. The good news: of more than 7,000 recorded bites in humans, only 10 resulted in death, and only 2% were severe enough to require medical treatment with antivenom. 

“Fun” Fact: This spider is also known as the "banana spider" because it often hides in banana leaves, which can lead to accidental human encounters. 

3. Brown Recluse Spider

Known For: Necrotic venom that destroys tissue   
Location: United States, especially in the southern and midwestern regions   

The Brown Recluse Spider, with its characteristic violin-shaped marking on its back, injects a unique venom that can cause necrosis, meaning it destroys tissue around the bite. While a bite doesn’t always lead to severe reactions, for some individuals, it can result in painful, slow-healing ulcers and systemic symptoms, like fever and muscle pain. Rarely, complications can escalate, leading to severe infections and tissue death that requires medical intervention.  

Fun Fact: Brown Recluse spiders sometimes play dead when they feel threatened. 

4. Black Widow Spider

Known For: Neurotoxic venom causing "latrodectism"   
Location: Worldwide, with higher populations in North America, Europe, Australia, and Africa   

Black Widows are easily recognizable by their shiny black bodies and the red hourglass mark on their abdomen. While their bites are rarely fatal, the venom can cause a condition known as latrodectism, characterized by muscle cramps, intense pain, and muscle spasms. Though medical treatment is sometimes necessary, fatalities from Black Widow bites are extremely rare, especially in healthy adults—for example, among 23,409 documented black widow bites between 2000 – 2008, zero resulted in death.  

Fun Fact: Female Black Widows are known for their habit of occasionally eating their mates after reproduction, which is how they got their name. 

5. Redback Spider
 

Known For: Close relative of the Black Widow with similar venom effects   
Location: Australia and Southeast Asia   

Redback Spiders are relatives of the Black Widow and share many of their traits, including the ability to inflict a painful bite with neurotoxic effects. A Redback bite can cause severe pain, sweating, muscle spasms, and in some cases, nausea and vomiting. Thanks to the availability of antivenom, no Redback Spider bite deaths have been recorded for decades. But these spiders can be dangerous, especially to children and the elderly. 

Fun Fact: Country artist Slim Newton won the Golden Guitar award at the first Country Music Awards of Australia in 1973 for his hit single, “The Redback on the Toilet Seat.” 

Safety Tips to Avoid Dangerous Spiders 

Check before you touch: Shake out clothes, shoes, and blankets that have been left outside or in dark spaces. 

Use Spider Traps: Spider traps like the RESCUE! Spider Trap can help keep spiders under control in your house, garage, shed, and other places they like to hang out. 

Keep a clean environment: Spiders are less likely to inhabit clean, clutter-free spaces. 

Wear gloves: When working in attics, basements, woodpiles, or gardens, gloves can reduce the risk of bites. 

Seek immediate medical help: If you suspect that you’ve been bitten by one of these venomous spiders and develop worrying symptoms, see a medical professional as soon as possible to ensure proper treatment.

While most spiders are not a threat, being aware of these dangerous species and taking simple precautions can go a long way to help you and your loved ones stay safe.