Dangerous Spiders in Brazil: 7 Species to Look Out For

Brazil wandering spider
Photo by kjwells86 on Envato Elements
The links on the website are in affiliation with Amazon Associates worldwide and we earn a small commission for qualifying purchases.

With its sweeping coastlines, colorful festivals, and renowned football scene, spiders are probably the last things that come to mind when you think of Brazil. In fact, it’s considered one of South America’s most diverse travel destinations while being home to some of the world’s most breathtaking landscapes and the infamous Amazon rainforest.

As such, it might surprise you to know that there’s more than just sunshine, great food, and a vibrant nightlife that tourists need to be aware of. Brazil is also home to a variety of spiders, but don’t worry, there are only a few in this country that pose any real danger to humans.

Still, it’s best to be on the safe side, so we’ve compiled a list of the most dangerous spiders in Brazil that you should look out for, to ensure you get the most out of your tropical getaway. Let’s get into it.

Brazilian Wandering Spider

Brazilian wandering spider
Photo by kjwells86 on Envato Elements

Brazilian wandering spiders, also known as armed spiders, have a particularly nasty reputation. As a matter of fact, they’ve been named the world’s most venomous spider by Guinness World Records on many occasions, and the name of the genus they belong to literally translates to “murderess’ in Greek. 

Seeing as its bite releases a neurotoxic venom that can be deadly to humans, and children, in particular, it comes as no surprise that it is among the most dangerous spiders in Brazil. Still, there is an antivenom, and the severity of the damage inflicted will depend on the amount of venom injected. Fortunately, these nocturnal arachnids are also quite big, with bodies reaching up to 2 inches and a leg length of up to 7 inches, so they shouldn’t be too difficult to spot.

That being said, it’s worth noting that these spiders vary in color, and although all are hairy, they’re usually brown and gray in color, and some have light-colored spots on their abdomen. They can also be distinguished by the bands of black and yellow or white on the underside of the two front legs, and the distinctive red jaws which they display when threatened. 

Brazilian wandering spiders usually seek cover during the day in houses, clothes, cars, boots, boxes, or log piles, and they’ve even been spotted within shipments of bananas. So, keep those eyes peeled.

Yellow Sac Spider

yellow sac spiders in Brazil
Photo by macropixel on Envato Elements

These tiny yellow spiders might not appear dangerous, and even seem cute in a way, but don’t be fooled, they pack a powerful punch. Their venom is a cytotoxin, meaning it can break down cells and slowly kill the area of flesh surrounding a bite, with the bite often being compared to that of a brown recluse. Even so, it is less severe, and the wound usually heals faster.

In the unlikely event that you’re bitten by a yellow sac spider, your best course of action would be to apply ice and elevate the bite site. Bites typically improve within a few hours or 2-3 days, but we recommend seeking medical attention immediately if the symptoms persist or worsen. You will most likely be prescribed antibiotics to prevent secondary infections. 

Yellow sac spiders are quite aggressive by nature, with female yellow sac spiders being prone to biting when defending their eggs, and bites typically occur when they’re trapped in clothing. 

Nevertheless, sac spider bites aren’t considered to be as serious as that of brown recluse or hobo spider, and the seriousness of bites varies greatly. Symptoms usually include an immediate burning sensation, similar to that of a hornet sting, which is followed by redness and mild swelling. In rare cases, a  person could also become mildly ill or be left with a blister, which could leave a wound that will heal over a few weeks.

Brown Recluse Spider

brown recluse
Photo by twenty20photos on Envato Elements

The infamous brown recluse spider, or violin spider, is well known not only for its highly venomous bite but for the distinction of having six eyes instead of the usual eight. They also have long legs as well as a nearly hairless body that measures roughly a quarter-inch with a dark violin-shaped marking on the back of the front portion, and they’re usually tan or gray in color. 

Its bite can sometimes lead to rotting skin lesions, while its venom targets phospholipid molecules, which make up a good portion of cell membranes, and transforms them into simpler lipids. The resulting wound could take quite a few months to heal, and there’s also the risk of infection, which can lead to death. 

However, only about 10 percent of brown recluse spider bites are dangerous, and the wounds generally heal very nicely, often without medical intervention or treatment. Nonetheless, we recommend applying ice to the wound and seeking emergency medical treatment, should you be bitten.

Hence the reclusive nature from which they get their name, they’re usually found in caves, rodent burrows, and other undisturbed spaces like attics, storage areas, and wall or ceiling voids. They usually travel in packs, so chances are there will be more lurking around the corner if you come across one.

Black Widow

black widow
Photo by twenty20photos on Envato Elements

Next up on our list, we have the notorious black widow spider. Their bulbous bodies, eight long legs, and bright red underbellies have made them one of the most easily recognizable arachnids, and a beauty to behold. Be that as it may, they are also undeniably one of the most dangerous spiders on earth.

Their name comes as a result of the female black widow’s tendency to eat her partners after mating, and while death from a black widow bite is fairly rare, they are still highly poisonous to humans. There are lucky individuals who are only slightly affected by a black widow bite, but they’re definitely in the minority. People have been known to suffer from nausea, muscle aches, as well as strained breathing due to paralysis of the diaphragm after being bitten, and they could be potentially fatal to children, the elderly, and the sick. The bite is also said to be excruciatingly painful.

Their preferred habitats are between boxes in storage spaces as well as shielded areas like attics and barns. That being said, they have terrible eyesight and catch prey, like flying and climbing insects, through vibrations in their web, so try your utmost not to accidentally stumble through them.

Wolf Spider

wolf spiders in Brazil

Photo by Anterovium on Envato Elements

Named for their wolflike habit of chasing and pouncing on their prey, wolf spiders are small to medium-sized arachnids who are less menacing than they appear. They are still undeniably venomous though, and avoiding them is best. 

Most wolf spiders are dark brown, with one-inch hairy bodies and stocky, long legs of the same length. They have a reputation for their sprightly running speed and usually find habitats in the grass, under stones, logs, or even leaf litter, but they have also been known to explore houses that harbor insects. 

Typically, they don’t spin webs, and most build silk-lined, tubular nests in the ground, which some conceal with rubbish, while others create turret-like structures above it. Another interesting tidbit about them is the fact that their eggs are stored in a grey silk sac attached to the female’s silk-producing organs, which makes it look like the spiders are dragging a large ball. 

By and large, they aren’t considered to be aggressive, but there have been reports of them biting people in self-defense. As mentioned above, these spiders are venomous, and victims who are allergic to spider bites could experience nausea, dizziness, and an elevated heart rate. As a result of the spider’s large fangs, the bite is also said to be painful, and this, combined with their speed and startling appearance, can lead to panic attacks as a result of the encounter.

Goliath Birdeater

most dangerous spiders in Brazil
Photo by twenty20photos on Envato Elements

Goliath birdeaters are one of the biggest tarantulas in the world, and despite what their name implies, they don’t often eat birds, although it has happened. They’re naturally prone to aggression, and this, combined with a leg span of up to 11 inches and a body length of around three inches, makes for quite an intimidating spider.

They’ve been known to attack humans in certain situations, with the bites causing intensive pain, which could last up to two days, coupled with discoloration at the bite site. 

Their fangs fold under the body, which means they have to strike downwards to impale their prey, and they often stand on their hind legs to show their fangs as a defensive maneuver. Fortunately, they also rub the hair bristles on their legs together to create a hissing noise that’s loud enough to be heard from 15 feet away as an additional defense system – great for warning you of their presence.

These spiders are generally solitary and typically found deep in the rainforest, under rocks and roots, as well as in silk-lined burrows. They’re also largely nocturnal. So, it’s best to avoid nature at night, unless you want to join the list of the mice, frogs, lizards, birds, and cockroaches they sink their teeth into.

Hobo Spider

hobo spider in Brazil
Photo by SKunevski on Envato Elements

Last but not least, we have the hobo spider, so named due to its tendency to hitch rides with humans along major highways. They’re particularly aggressive as far as spiders go, so it’s best to be on the lookout for this arachnid if you’re heading to Brazil. 

With lean hairy brown legs and abdomens with several chevron-shaped markings, most grows to about half an inch long. They’re typically found in dark, moist habitats near ground level, since they’re poor climbers, meaning they often make basements, window wells, or crevices their home. While their venom might not be considered lethal, it has a similar effect to that of a recluse spider, and common bite symptoms include a severe headache and an open wound with an extensive healing period.

Naturally, it would be best to avoid them. We advise screening all the doors and windows of your place of residence and getting rid of clutter in basements and garages to eliminate possible hiding spots. It would also be a good idea to proceed with caution when moving items that have been stored for a long period of time.

Are there poisonous spiders in Brazil?

There are a number of poisonous spiders in Brazil, in fact, some of the most venomous arachnids in the world call the Amazon rainforest home. There are eight known species of the Brazilian wandering spider alone, one of the most formidable and sizeable tarantulas and the most venomous according to the Guinness Book of World Records. Still, black widow spiders, brown recluse spiders, and Goliath birdeaters, among others, are all venomous arachnids that can be found in Brazil. 

What happens if a Brazilian wandering spider bites you?

Regarded as the most poisonous arachnid ever, a bite from a Brazilian wandering spider would cause intense pain, burning, swelling, and shooting pains at the bite site. The most common cause of fatalities is allergic reactions, which can lead to immediate anaphylactic shock and cardiac arrest, and this remains a general risk for the ill, elderly, or very young. Infection is also a big cause of death with spider bites that aren’t properly tended to, and wounds can last for months. A wandering spider’s bite can also cause priapism, a potentially harmful and painful genital side-effect that can lead to impotence. 

Which country has the deadliest spiders?

Brazil might be home to more deadly creatures than any other country in the world, but Australia has more deadly spiders by volume than Brazil. The number of venomous arachnids in the land Down Under has earned it quite a scary reputation, but the chances of being killed by a spider in Aus are quite small. Most of the world’s largest spiders can be found in Brazil, but this doesn’t mean they’re always the most venomous.   

Previous articleJamaica Or Mexico: Which Destination Is Right For You?
Next articleIs Lombok Worth Visiting? 9 Reason’s to Visit Bali’s Neighbor
Esmé is an English literature graduate and freelance writer. Originally from London, Esmé is lucky enough to call Bali home. Her travels have taken her from the far corners of the East to the islands of the Caribbean. When she's not writing, you'll find her lying on a beach somewhere, lost in a crime novel.