Arachnophobia is one of the most common fears across the world, so many people are terrified by eight-legged creepy crawlies. The fact that there are more than 40,000 different species of spiders on earth might scare arachnophobes, but only a handful can be dangerous to humans. Less than 30 species of spiders have been responsible for the death of humans, so this common fear is much more unlikely than you think.
All spiders are venomous by definition, they all have fangs that inject a toxin into the body of their victim. However, the vast majority of spiders are only dangerous to small animals and insects; humans are much too large to suffer. To produce an allergic reaction or another toxic effect large enough to seriously harm a human, the bite must be from one of the most venomous spiders in the world. Even in these cases, modern hospitals and poison control centers have advanced antivenom to combat the toxins.
One common misconception about dangerous spiders is that they are poisonous, but there is no “most poisonous spider” to list. Spiders are venomous as they intentionally inject a toxin- poison is a passive threat. If you were to eat a spider and suffer harmful effects, it would be poisonous. However, spider bites are venomous, and this is an important distinction to remember.
In this article, we’re going to tell you about all of the deadliest spiders in the world. We’ve included 10 of the most venomous spiders known to man, each with a powerful toxic pair of fangs. Bites from these deadly eight-legged creatures can cause terrible pain, huge necrotizing wounds, and even be fatal to humans. From aggressive predators to shy but lethal creepers, let’s jump into the 10 deadliest spiders in the world.
It’s no surprise that many of the most venomous spiders are found in Australia. The Sydney Funnel-Web can only be found within a 60-mile radius of the city, meaning its habitat is the place most densely populated with humans in the entire country. Funnel-Web spiders are incredibly aggressive towards predators and will pounce on humans rather than flee or hide.
The Sydney Funnel-Web Spider, or Atrax Robustus, has venom so strong that it can kill in just 15 minutes. While it’s usually the females which are more dangerous amongst arachnids, male Funnel-Webs are the ones with the venom. These spiders have large sharp fangs, which will cause extreme pain at first bite. Then, victims will suffer neurotoxic effects such as vomiting, muscle spasms, and low blood pressure. Around 10% of serious Sydney Funnel-Web bites will cause a person to fall unconscious or into a coma, a high percentage in comparison to all other spiders.
One surprising fact about this spider’s venom is that it’s very effective on humans and other primates, but does little damage to other small animals like rabbits. That means it is specifically one of the most dangerous spiders in the world to humans. Even so, only 1 out of 10 people bitten by the Antrax Robustus require medical attention, and no-one has died since the antivenom was introduced. Before that, the most venomous spider in the world had only killed 14 people.
The Black Widow Spider is one of the most famous dangerous animals on the planet. It’s instantly recognizable from its round black abdomen with bright red markings. This spider is the most common member of the Latrodectus family found in North America. They’re most common in the southern states and California. The venom of the Black Widow is in theory 15 times stronger than that of a rattlesnake, producing muscle aches, nausea, and paralysis of the diaphragm which can cause breathing problems.
Despite the strength of their venom, there have been no deaths attributed to Black Widow Spiders in the US. These arachnids are more likely to bite insects than humans, and will rarely attack humans unless in self-defense. Female black widows are usually about an inch in size, and sport an hourglass shape on their underside. Males are much smaller, and often show red or white stripes in addition to the hourglass. Black Widow bites were known to kill the very young and elderly before the introduction of the antivenom, but nowadays they aren’t much of a threat to humans.
Another strong contender for the most venomous spider in the world is the Brazilian Wandering Spider, a member of the Phoneutria family. Large and brown in color, this arachnid looks very similar to North American Wolf Spiders but is much more deadly to humans. Luckily, these spiders only bite people when alarmed, which can happen if they crawl into human habitats for the night. Brazilian Wandering Spiders like to sleep in fruits or flowers which humans might have cultivated, which is the most common cause of spider encounters. These arachnids are also known as banana spiders because of their love for the fruit.
Unless you startle or aggravate a Brazilian Wandering Spider, it will likely deliver a dry bite. This might surprise you a bit, but no venom will be injected. Should you harm the spider, a highly venomous and painful bite could be your payment. This spider’s toxins can cause severe muscle shock, which can be fatal even after the antivenin is administered. Children are more susceptible as they have weaker immune systems, so the Phoneutria fera’s strong venom can sometimes take over.
The Latrodectus family contains so many of the deadliest spiders in the world, including the Black Widow and Australian Redback Spider. Another highly venomous spider in this family is the Brown Widow, a close relative of the black but with different neurotoxic effects. You can recognize a Brown Widow by one or several red spots, which could take the form of an hourglass or sit in a row.
Brown Widow Spiders are highly venomous but seldom deadly. Their bite causes painful muscle spasms and contractions, and in worse cases spinal or cerebral paralysis. These effects are usually temporary, but can permanently damage your central nervous system. Serious bites are much more dangerous to children, the elderly, and those with pre-existing illnesses. You might want to use a bug net to keep these away on your next camping trip.
5. Brown Recluse Spider/ Chilean Recluse Spider
The Loxosceles reclusa, or Brown Recluse Spider, is one of the most venomous spiders found in the United States. Its venom is different to most neurotoxins which spiders carry, in that it causes devastating effects around the site of the bite only. Brown Recluse bites destroy the walls of surrounding blood vessels and can cause a large wound which may take months to heal. You’re at more risk of death from infection of this wound than from the venom itself, but this spider is still one of the most deadly in the world.
The west and south of the US are the most likely place to find Chilean Recluse Spiders. You might also know them as violin spiders or Fiddlebacks, as many people think their design looks like a dark violin shape. This spider generally lives in caves and rodent burrows, and sometimes can move into quiet places in buildings such as attics. Brown Recluse Spiders usually stay away from humans, but if you come across one steer well clear of its highly venomous fangs.
The Tarantula is one of the most iconic and terrifying spiders known across the world, but most bites from these spiders are no worse than a bee sting. However, this isn’t the case for the Fringed Ornamental Tarantula or Poecilotheria. This arachnid is endemic to Sri Lanka where females can reach a gargantuan size of ten inches. The Poecilotheria feeds on insects and there has never been a recorded death among humans, but their bite can cause intense pain.
The venom from this Tarantula can cause severe muscle cramping and excruciating pain, sometimes requiring a trip to the emergency room. While it isn’t the most venomous spider on our list, the Fringed Ornamental Tarantula injects a whole lot of venom with its bite; you definitely want to avoid this hairy eight-legged beast.
The Yellow Sac Spider is relatively small, as the largest are rarely longer than half an inch. Despite being smaller than most of the other spiders on this list, the Yellow Sac is one of the most likely to bite you. A huge portion of worldwide spider bites come from Yellow Sacs, so they’re definitely among the most deadly. You can easily recognize this arachnid from its yellow colored body, accompanied by brown markings on the body and feet.
Yellow Sac Spiders are native to the Americas, generally living in forests in leaves or grass. These spiders can sometimes move into human homes, where disturbing them can lead to disaster. Female Yellow Sacs will bite to defend their eggs, so try not to provoke this venomous spider. Upon biting, this arachnid injects a cytotoxin which destroys and impairs the cells around it. This can cause rashes, blistering, and welts with necrotic centers. More severe symptoms including fever and general sickness can last for up to 10 days after the bite.
The Six-Eyed Sand Spider has one of the most venomous spider bites on record. It’s a relative of the recluse spider, found in Africa and South America. There have been nearly 40,000 different species of the six-eyed sand spider identified, but the true figure could be much more. These spiders are incredibly good at hiding, leading humans to believe up to 200 thousand species of this spider are out there.
This arachnid is covered in tiny hairs that hold particles of sand. These provide camouflage even when the spider is not buried, making it an excellent predator. Six-eyed sand spiders can grow up to 2 inches in width, and generally around 0.6 inches in length. They are reddish-brown to yellow in color however will camouflage with any environment. Unlike most web-spinning spiders, the six-eyed does not hunt with a trap. Instead, they wait buried under the sand until they can ambush their prey.
The Six-eyed Sand Spider eats insects and scorpions, biting and then consuming them if they can make a catch. This spider doesn’t need to eat often and can survive for a very long time with no food or water. As one of the most venomous spiders in the world, we should be glad that the six-eyed sand spider is very shy. Studies have proven its venom incredibly dangerous to humans, as a powerful hemolytic toxin which destroys red blood cells.
Unlike the other deadliest spiders in the world, there is no antivenom currently available for the six-eyed sand spider’s bite. This is definitely one of the most venomous spiders in existence, but the threat to your life is minimal. There has never been a confirmed case of a six-eyed bite, but the suspected bites had nasty results. The effects are similarly painful to rattlesnake bites, so we would recommend steering clear.
9. Mouse Spider
Mouse Spiders are found in Australia, generally 10 to 35 mm in length. They have distinctly bulbous bodies colored black or blue, with a light-colored patch on top. Mouse Spiders are commonly confused with Funnel Web Spiders, as their bite has many of the same symptoms. However, Mouse Spiders are much less likely to invade densely populated areas, as they are not generally urban predators. Instead, Mouse Spiders live in forests and shrubland in large, silk-lined burrows.
Mouse Spiders use trap doors to capture their prey, as well as hide from potential predators. The female mouse spider can remain inside her burrow for her entire life unless accidentally dug up. Any creature small enough to pass by the mouth of a mouse spider burrow might be a bite victim; these arachnids are opportunistic eaters. They are also generally non-aggressive unless provoked.
The usual prey of the mouse spiders is insects, but other arachnids and small vertebrates can fall victim to their venom. The venom of these spiders is highly toxic to humans, in a similar way to the Sydney Funnel-web. However, Mouse Spiders are thought to most often deliver a “dry bite” to humans, making it much less dangerous. Their bite is undoubtedly toxic to humans, but funnel-web antivenin has been proven effective treatment.
This arachnid is one of Australia’s native Tarantula species, and one of the more dangerous members of this family. The whistling tarantula is also called the barking tarantula due to the singular sound it can make when provoked. This spider isn’t particularly deadly to humans, however, it’s long 1cm fangs deliver a painful bite.
Whistling Tarantula venom isn’t strong enough to kill animals as large as humans, but it’s potent enough to finish off a large dog in less than half an hour. The venom can cause intense pain and up to eight hours of vomiting, as well as serious swelling. Although the Whistling Tarantula’s bite isn’t life-threatening, you need to seek medical attention straight away should you fall victim.
This spider can reach a length of 6 to 9 cm, making it the largest Australian Tarantula. It’s actually the biggest spider in the whole country, easily recognizable by its thicker front legs. Female Whistling Tarantulas can live an impressive 30 years. If you’re out hiking and hear a hissing sound coming from the underbrush, watch out for this venomous arachnid.
It doesn’t matter if you live in the middle of the forest, or at the top of a city-center high rise; you’re never that far from a spider. There are tens of thousands of different species of spiders all around the world, not including those yet to be discovered. A fear of spiders is highly common, but in actuality, these eight-legged creepers don’t present much critical threat.
Only a handful of spider species are capable of harming humans, and a much fewer percentage can administer a fatal bite. However, you can never predict how an individual’s immune system will respond to venomous toxins, so caution is always advised. Luckily for us, humans aren’t the natural prey of any dangerous spider, so most of the time bites are easy to avoid. Take a look at the Brazillian Wandering Spider; it has some of the most potent venom out there, which can even overpower antivenins in certain cases. On the other hand, this spider rarely delivers a bite powerful enough to kill humans. The spider is more likely to bite out of shock, without injecting venom into the victim.
The Sydney Funnel-Web poses a different threat, as this spider prefers to habitat in densely populated areas, and is known to be very aggressive towards humans. This venomous spider will even jump onto its prey to deliver a bite. The venom causes vomiting, nausea, and more concerningly induce comas in around 10% of patients. This arachnid, and every single other spider on our list, are the deadliest and most venomous known to man.
Bonus tip: Check out this creepy video of the whistling tarantula!