The 15 Deadliest Spiders in the World

Of the thousands of different spider species, each has unique adaptations to survive in their respective habitats. Notably, certain spiders have evolved potent venom to help them take down prey. Such a weapon makes these spiders formidable predators. Unfortunately, it also makes them extremely dangerous to humans. Certain spider species can take down dozens of insects each day and some even hunt small animals such as mice. 

Redback Spider

Fellow countryman of the fearsome funnel web, the redback spider also calls Australia home. It has highly potent venom which, while not as intensely deadly as the funnel web, can cause significant discomfort and distress. Known for its distinctive red stripe down its back, this spider’s bite often requires medical attention to treat the pain and swelling. 

Chilean Recluse Spider

Often found in warmer climates, the Chilean Recluse Spider is highly venomous. Their bite can cause skin necrosis and systemic illness. Being reclusive by nature, these spiders lurk in hidden areas, increasing their danger to unsuspecting victims. If bitten by one, immediate medical assistance may be necessary. 

Brazilian Wandering Spider

This arachnid doesn’t live up to its name as it is typically found in Brazil but also throughout South and Central America. The venom it carries is neurotoxic, causing severe pain, paralysis, and possibly death if left untreated, so immediate intervention is necessary if bitten.

Katipo Spider

This rare spider species lives in New Zealand and sports a shiny black or brown body with a white and red patterned abdomen. Their venom contains a potent neurotoxin, which can cause pain, sweating, rapid heart rate, and in some severe cases, abdominal cramping. However, bites from Katipos are extremely rare (though you should still avoid them altogether).

Brown Recluse Spider

The Brown Recluse Spider is an elusive spider species that primarily lives in the southern and midwestern parts of the US. The brown recluse has a highly potent cytotoxic venom, which can cause severe tissue damage and necrosis. While they’re not aggressive and typically bite only when threatened, it’s best to keep your distance if you spot one. 

Black Widow Spider

North America’s most venomous spider, the Black Widow, earns its name from its deadly mating behavior. It can easily be identified by its shiny black appearance and the distinctive red hourglass mark on its underside. This spider’s venom is 15 times more potent than a rattlesnake’s, which is bad news for its prey. Fortunately, medical advances have drastically improved the survival rate of bitten humans. 

Six-Eyed Sand Spider

Found in deserts in southern Africa, the Six-Eyed Sand Spider is an exceptional hider, often burying itself in the sand with only its eyes and part of its cephalothorax visible. While human bites are rare, its venom can be lethal, causing blood vessel leakage, blood thinning, and tissue destruction. 

Brown Widow Spider

Brown Widows live across the globe, but particularly in the warmer regions of the United States. This relative of the infamous Black Widow also packs a potent venom. It’s less dangerous than its black cousin because it releases a much smaller amount of venom, but its bite can still result in severe pain and other uncomfortable symptoms. 

Red Widow Spider

The Red Widow Spider is a species exclusive to Florida’s sand dunes. It has bright red legs and red or orange marks on its belly. Unlike its Black Widow relative, the Red Widow often does not have the complete hourglass shape on its abdomen. Its neurotoxic venom causes severe muscle pain and cramps in humans, making its bite just as harmful as that of its better-known cousins.

Funnel Web Spider

The Funnel Web Spider’s primary habitat is in Australia. Widely recognized as the world’s deadliest spider, it carries venom packed with 40 different toxic proteins. These proteins can cause life-threatening reactions in human victims. When encountered, this aggressive arachnid is best left undisturbed.

Yellow Sac Spider

Found in many parts of the world, Yellow Sac Spiders are notorious for biting without provocation. Their venom isn’t as potent as some other spiders’, but can still lead to pain, redness, and swelling around the bite site. They also aren’t picky eaters and will consume moths, flies, mosquitos, and other spiders, making them one of the deadliest spiders in the insect world. 

Mouse Spider

The Mouse Spider is native to Australia and it has a very nasty bite. Although bites are extremely rare, their venom can cause serious symptoms including severe pain, vomiting, and, in some severe cases, necrotic ulcers. In most of the already rare human bite instances, the Mouse Spider will ‘dry bite’, meaning they may pierce the skin but will not release any venom. 

Camel Spider

The Camel Spider has two massive jaws that can be up to one-third of their body length. But they don’t carry any venom. Instead, they release a specific concoction that lets them digest prey while its alive. Their bites can be painful to humans and sometimes lead to infection and deep wounds if not treated properly.

Northern Tree-Dwelling Funnel Web Spider

The Northern Tree-Dwelling Funnel Web Spider should not be confused with its equally deadly cousin, the Sydney Funnel Web Spider. Their venom contains robustoxin, a potent neurotoxin that can cause severe issues making these spiders some of the most dangerous in the world. They’re also very aggressive, so caution is necessary when treading through their territory.

Mediterranean Black Widow Spider

This venomous creature is found throughout the Mediterranean region, even reaching certain parts of Central Asia. The Mediterranean Black Widow’s venom is neurotoxic, causing severe muscle cramps, abdominal pains, and even breathing difficulties in humans. The bite might not always be fatal, but it does require immediate medical assistance to mitigate health risks. 

12 Scary Creatures of the Planet

12 Scary Creatures of the Planet