Top 10 Most Venomous Spiders On Earth

While the southern black widow is among the most well-known and feared spiders, is its bad reputation accurate? This arachnid is relatively common in certain areas in the United States. Females of the species are often identified by a unique hourglass marking. Only mature females have large enough jaws to envenomate humans; bites can cause muscle aches, swelling, or even make it difficult to breathe. Luckily, most adults tend to recover. But this spider’s venom is still dangerous to vulnerable groups like children and the elderly. If bitten, they should seek immediate medical attention.

Some spiders prefer to mind their own business and stick to the shadows. However, the yellow sac spiders are bold predators. The rather tiny size of this creepy-crawly allows it to get around easily. This enables it to go from being a rather irritating garden arachnid to a persistent unwanted house guest. Certain species of yellow sac spiders can produce a bite that usually results in swelling and discomfort. But as with most spiders, reactions can vary from person to person. In rare instances, a yellow sac spider could leave its victim feeling sick enough to want to visit a doctor.

Although it’s not as famous as its cousin, the brown widow is still a species to look out for. With striped legs and an orange hourglass on its body, the brown widow has quite an eye-catching look. Fond of tropical locales and known to hide around barns and houses, the brown widow will not usually seek out human contact. While the males don’t bite, the females of the species will if threatened. Some researchers believe that its venom is much more potent than the black widow’s! Luckily, brown widow spider bites don’t usually deliver a large quantity of venom.

Traditionally located in southeastern and central eras of the United States, the brown recluse typically comes stamped with a violin pattern on its body and maxed out stealth skills. The spider's name is not simply for show, as the brown recluse sticks to well-hidden areas and seldom brings attention to itself. Its venom is necrotic and can be unpredictable. While some people might end up with nausea and a reddish mark that fades without complications, others can develop a blister or a lesion susceptible to gangrene. Luckily, the brown recluse doesn’t often bite deeply or frequently.

Compared to some other species that call Australia home, the red-headed mouse spider almost comes across as quaint. It’s a black spider with an instantly recognizable bulging head that is very red in males. The mouse spider likes to stick to burrows near water routes, thus making human contact relatively rare. But humans who do encounter it should remember that this spider has a highly toxic venom. While a bite from a red-headed mouse spider has rarely led to severe symptoms, victims are better off playing it safe and getting checked out.

Found in southern African deserts and somewhat resembling a crab, the six-eyed sand spider spends its days setting traps to eat insects and scorpions. This arachnid predator is mainly the type to keep to itself and pretty much wants nothing to do with humans. Its behavior has made bites involving the species almost unheard of. And that is very much a good thing, as the spider's venom is suspected to be toxic enough to cause necrosis, killing the tissue around the bite. Oh, and did we mention there’s currently no antivenom? Although the spider's introverted nature keeps it from being a threat to humans, it still has enough firepower behind its fangs to be a danger.

The Chilean spider is widely considered to be the most dangerous arachnid in the recluse genus. A South American native that’s indulged in some sporadic immigration, the Chilean recluse spider has six eyes and often bears a violin marking on its thorax. It’s very fortunate that this arachnid likes to keep its distance from humans because its venom packs a hefty punch. The Chilean recluse's bite is toxic enough to result in fatal consequences if enough venom is injected. But even in less severe cases, the spider's venom is necrotic and can lead to loxoscelism, a condition that can take months to heal.

Now for another Australian resident. Also known as the Australian black widow, the redback is from the same genus as the widow spiders earlier in our list. The female of the species has a red stripe on its body, is considerably larger than the male, and has way more dangerous bites. Although they don’t go out of their way to attack humans, redback spiders have been known to settle down in areas that bring them into contact with people. This makes biting incidents much more likely. Their toxin is known for causing intense pain and other symptoms like nausea and sweating. Fortunately, an antivenom introduced in 1956 has helped lower the chances that these spiders will strike a fatal blow.

It’s best to stay out this spider’s way when it goes on a stroll. A proactive hunter, the Brazilian wandering spider is hairy, large, and extremely venomous. Instead of just setting up webs, this species goes for walks to find its prey. The spider's bite can produce a range of alarming symptoms, including hypothermia, vertigo, and convulsions in humans. If enough venom is injected, the wound could be life-threatening. Fortunately, the Brazilian wandering spider only tends to bite humans with a relatively low amount of venom when it’s provoked. And if you have a bad encounter with this arachnid, an anti-venom does exist.

Funnel-web spiders have earned quite a nasty reputation. However, not every species is equally dangerous. While the northern tree-dwelling variant should be taken seriously, the one you should really worry about is the infamous Sydney funnel-web spider. Inhabiting the area around Sydney, the capital city of New South Wales in Australia, these spiders like to dwell in humid habitats. Like most spiders, they usually only bite humans when feeling threatened. But that knowledge will probably be of little comfort to its victims. They often clutch onto their target and bite again and again. The potent venom from males can cause intense pain, muscular twitches, and disorientation. In worst-case scenarios, a Sydney funnel-web spider’s bite can be fatal if it’s not treated.