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MOST spiders are totally harmless – but a select few can give you serious trouble if they bite.

Complications from some of Earth's deadliest eight-legged biters include painful erections, vomiting, organ failure, and even death.

The Brazilian wandering spider, seen here on a tree in Peru, can bite you if disturbed
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The Brazilian wandering spider, seen here on a tree in Peru, can bite you if disturbedCredit: Getty - Contributor
The critter – also known as the banana spider – has been linked to several deaths
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The critter – also known as the banana spider – has been linked to several deathsCredit: Alamy

BRAZILIAN WANDERING SPIDER

One of the most dangerous spiders to find digging its fangs into your flesh is the Brazilian wandering spider.

They're typically found in northern South America (including Brazil), and can grow to a legspan of around seven inches.

Its official name is Phoneutria, from the Greek "φονεύτρια" – which means "murderess".

This is appropriate given it's one of the few spiders that can actually threaten humans.

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They'll often hide in places where you might end up sticking a body part, like in clothes, shoes, and boxes.

And if you disturb them, they may bite.

The spider has been linked to several deaths, and can kill in hours.

For men, it can also cause a condition called priapism, which is a long-lasting and painful erection.

Thankfully anti-venoms are available to treat bites, reducing the risk of death.

And here's a fun fact: they're also known as the "banana spider" because some people believe they've been found abroad in shipments of bananas.

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BLACK WIDOW SPIDER

Probably the most famous of the deadliest spider lot, the black widow almost needs no introduction.

Officially known as Latrodectus, its species can be found on every continent in the world.

A bite from a black widow can cause significant muscle pain, tummy cramps, sweating, fast heart rate, and spasms.

Many bites don't inject venom, and even envenomated bites don't always result in serious symptoms.

Only female black widow spiders – like the one seen here – bite humans
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Only female black widow spiders – like the one seen here – bite humansCredit: Getty

However, there is a very low risk of death for the young, elderly, and anyone with a weakened immune system.

They're notable for having a red hourglass marking on their dark brown or black bodies.

And females are the biggest of the black widows, with legspans coming in at around 1.5 inches.

They rarely bite, and will usually play dead – but can chow sink their fangs into a human if they're trapped, squeezed or pinched.

AVOID BLACK WIDOW BITES

Here's the official advice from the USA's National Capital Poison Center...

Protect yourself in areas where they might live.

  • Shake out your gardening gloves before putting them on. Shake out boots or shoes that you've stored in garages, basements, or sheds before putting them on.
  • Always wear gloves when moving wood, reaching into wood piles, handling mulch, grabbing empty flower pots, etc.
  • If you'll be working in a garage or shed, or under a porch or deck, wear a hat to protect your head.

Picture Credit: Getty

A black widow may bite if they're squeezed or pinched
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A black widow may bite if they're squeezed or pinchedCredit: Alamy

If you are bitten, symptoms usually last between three days and a week – but can persist for longer.

SYDNEY FUNNEL-WEB SPIDER

The Sydney funnel-web spider (Atrax robustus) can cause serious illness and even death in humans.

Thankfully it's typically only found in eastern Australia, largely around Sydney.

It delivers a very painful bite, and can even stay attached to you until you try to flick it off.

Australia's Sydney Funnel Web spider is a deadly creature with a powerful bite
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Australia's Sydney Funnel Web spider is a deadly creature with a powerful biteCredit: Getty Images - Getty

The spider is defensive, and typically delivers "full envenomation" with a bite, potentially even striking repeatedly.

Symptoms after a bite might include intense nausea and vomiting, muscular twitching, difficulty breathing, confusion, and even unconsciousness.

It's usually considered to be a medical emergency, and requires fast administration of antivenom.

According to the University of Melbourne, death in humans can occur in "as little as 15 minutes".

This is largest male specimen yet of the Sydney funnel web spider, a 3.1-inch critter nicknamed Hercules
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This is largest male specimen yet of the Sydney funnel web spider, a 3.1-inch critter nicknamed HerculesCredit: Live Science

Thankfully deaths are now very rare due to the development of effective antivenom.

BROWN RECLUSE SPIDER

The brown recluse – or Loxosceles reclusa – is one of the only spiders in North America with dangerous venom.

It often has a violion-shaped marking on its body, giving rise to nicknames like the fiddleback spider or brown fiddler.

The spider is notable for having potent necrotic venoms, meaning they destroy tissue.

The Brown Recluse Spider can be found in the United States, and has potentially dangerous venom
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The Brown Recluse Spider can be found in the United States, and has potentially dangerous venomCredit: Alamy

This can result in something called loxoscelism where the skin around the bite dies.

And it can also lead to symptoms like nausea, vomiting, and a fever.

It's a reclusive spider so bites are rare – and will typically only strike if pressed against skin.

This can happen if the spider was hiding in a long-unworn item of clothing, bedding, shoes, or gloves.

The bite can cause necrosis, or death of the skin around the site of the strike
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The bite can cause necrosis, or death of the skin around the site of the strikeCredit: Alamy

Very rarely, bites can cause system symptoms that result in blood clots, organ damage, or death.

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But it's typically the very young, elderly, or immune-compromised that are at risk of serious complications.

Wound infections are also rare, but can be treated with antibiotics if diagnosed.

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