The largest country in South America is a wonderland of biodiversity. Since it is home to both the largest rainforest and largest tropical wetlands in the world, it is no surprise that it would contain an astounding array of plants and wildlife. Unfortunately, it’s also no surprise that Brazil is home to many dangerous animals.
Brazil has a highly aggressive and carnivorous giant centipede and an 8ft long eel capable of giving out electric shocks. But neither of those creatures even made it onto our list! The diverse ecosystems of Brazil provided us with far more interesting and deadly animals than that. Like an insect with the most painful sting in the world and a tiny amphibian that could kill whole tour groups without even trying.
So don’t take any trips to the Amazon without preparing yourself with our list of some (but not all) of the most dangerous animals in Brazil.
Table of Contents
Sharks
Sharks have always lived around South America, and there are currently around 90 species of sharks and rays living in the waters around Brazil. But unfortunately, incidences of shark attacks have risen sharply in recent years, especially around the northeast coast of Brazil.
Recife is a popular tourist destination with many beautiful beaches, including sadly, one of the most shark-infested beaches in the world. But this wasn’t always the case; Recife had no more shark attacks than anywhere else in Brazil until the construction of a large shipping port in the area. Now, since the 1990s there have been 47 shark attacks along a 20 km stretch of coastline, shark warning signs are a common feature along Recife’s beaches, and Brazil ranks as the 5th most dangerous country for shark attacks in the world.
The shark held responsible for most of these attacks is the Bull Shark, one of the world’s top three most dangerous sharks. Broad, stocky, and powerful, bull sharks can grow to 13 feet long and weigh around 300kg. They enjoy warm, shallow ocean waters, hence their regular contact with swimmers, but can also thrive in fresh water and regularly migrate up rivers. It is the closing of several estuaries by the new shipping port that is thought to have led to the sudden change in the bull shark’s habitat.
Caiman
Six species of Caiman live in Brazil and South America, ranging from the 6kg Cuvier’s Dwarf Caiman to the much larger Black Caiman, which can weigh up to 500kg. This fearsome crocodilian is one of the most dangerous and feared animals in Brazil.
As the name might suggest, the black caiman has dark scales which render it tricky to spot in the murky waters and mud of the rivers, lakeshores, and floodplains on which it lives. At 16ft long, this monster is considered the largest predator in the Amazon Basin and lives on a varied diet of birds, reptiles, fish, and mammals. An indiscriminate hunter, it will try its luck on any creature that crosses its path, including jaguars, cattle, anacondas, and river dolphins. It hunts mostly at night, helped by its dark hide and excellent sight and hearing. Its method is to pounce on its unsuspecting prey before crushing it or dragging it underwater to drown it.
As these reptiles are opportunistic hunters, they will hunt and kill humans for food if given the chance, so visitors are warned to stay out of all caiman habitats after dark.
Jaguar
The beautiful symbol of South America, the Jaguar, has lost almost half its habitat to deforestation and development. These days Brazil is the last stronghold of these animals with half of their remaining number living in the Amazon and Pantanal. The Pantanal wetlands are one of the few places where you might see one of these elusive animals in the wild.
Although they are only the third biggest cat in the world, after lions and tigers, the jaguar is considered the most powerful. They kill most of their prey with a crushing bite to the back of the skull. And their teeth and jaws can crack open turtle shells and even penetrate the thick hides of Caiman, making them one of the most dangerous animals in Brazil.
Brazilian Wandering Spider
These spiders do not build webs to catch prey like other spiders but wander the forest floor at night, actively hunting for prey. They live off insects, small reptiles, and rodents which they immobilize and kill with their toxic venom.
First discovered in Brazil, this spider is actually found all over South and Central America. And thanks to its habit of stowing away in banana boxes, it has also been found in grocery stores all over the world. The discovery of these ‘banana spiders’ in the produce section understandably causes panic since they are large (with a leg span of up to 7 inches), aggressive, and venomous.
A bite from a Brazilian wandering spider is potentially deadly for humans. Symptoms can include severe pain, swelling of the bitten limb, fever, nausea, shock, vision impairment, and rapid heart rate. Fatalities are often due to respiratory failure and can occur within a few hours if no treatment is given. Therefore, any bite by this spider should be taken extremely seriously.
Poison Dart Frog
As is often the case in the animal kingdom, those who wear the most brilliant colors can be the deadliest. This is certainly the case with poison dart frogs, one of the most beautiful and dangerous animals in Brazil and South America.
These frogs are only tiny, with the largest growing to around 2.5 inches long. And their jewel-bright colors serve as a warning to potential predators that these frogs are highly toxic and not worth eating. They only have one predator, the Leimadophis Epinephelus, a strong-stomached snake that is resistant to the frogs’ toxicity and can feed on them without ill effects.
Their name comes from the fact that Native American’s once used their poison to coat the tips of arrows and darts before using them. A highly effective method of killing since the poison of one of these tiny frogs is potent enough to kill ten people. Although this may sound concerning, these frogs are not predators. They won’t chase, hunt, bite or sting you. Their toxins are in their skin, so unless you touch them (or get shot by a poison dart), you shouldn’t have anything to worry about.
Bullet Ant
This ant is supposedly responsible for the most painful insect sting in the world. When this 1.2-inch long ant stings, it is said to feel like being shot with a bullet, hence the name. They are not aggressive towards humans unless they feel that their nest is being threatened, in which case they will defend it vehemently, stinging their target repeatedly.
The extreme pain caused by these stings can last up to 24 hours and is so intense that Brazilian tribes used the bullet ants in initiation rituals for young warriors. The unlucky initiate would have to put on a glove filled with angry bullet ants and try to keep it on for a certain length of time. We do not recommend testing your nerve in such a way!
The ant’s sting is not only painful but contains a paralyzing toxin, which can lead to trembling and swelling of the limbs, swelling of the lymph nodes, and rapid heart rate. And Justin O. Schmidt, who has been stung by 150 species, described the pain from a bullet ant sting as “Pure, intense, brilliant… Like fire-walking over flaming charcoal with a three-inch rusty nail grinding into your heel.”
Piranha
The Piranha’s reputation as a ferocious and ravenous predator has been somewhat exaggerated by the media. There are elements of truth to it, such as the Piranha’s powerful jaw and razor-sharp teeth, incongruous with a fish of its size. However, the truth is that most piranhas are scavengers more than hunters. Some of them only eat other fish, and some are even vegetarian.
It is thought to be the red-bellied piranha that led to the fearsome reputation now shared by the whole species. The red-bellied piranha travels in shoals, and although they don’t actually hunt in a pack, they have been known to enter into feeding frenzies during which they can strip an animal carcass in a matter of minutes. However, these frenzies happen rarely, usually during times of starvation.
Most piranha attacks on humans in Brazil involve painful bites to the feet, legs, or hands but are very rarely severe or deadly. That being said, there have been some fatalities. So, since these carnivorous fish are attracted to splashing, noise, and blood in the water, you would be wise not to swim near fishermen using bait, and should not allow children to play in waters thought to house piranhas.
Green Anaconda
The Green Anaconda is the biggest, longest, and heaviest snake in the world and lives throughout Brazil and South America. Its favorite habitats are slow-moving waterways, swamps, and streams. But it can also live in caves, as these Brazilian workers discovered when they found a 33ft, 400kg monster living in their proposed construction site.
These giant, semi-aquatic reptiles are rather ungainly when viewed on land but move gracefully and stealthily through water, their favorite hunting ground. With their eyes and nostrils located on the top of their head, they can lurk, semi-submerged in water, waiting for unsuspecting prey to come along.
They are non-venomous constrictors, meaning that rather than biting their prey, they wrap their massive coils around it and slowly squeeze it to death before swallowing it whole. This method is effective on huge prey, including jaguars and caiman. Although this idea is rather terrifying and gains the snake a firm spot on our dangerous animals list, cases of anacondas killing humans are extremely rare in Brazil. These snakes are not particularly active predators, often catching only one meal in months. It takes the anaconda hours to swallow its large prey, then even longer to digest it. Afterward, they may not eat again for weeks at a time.
Pit Viper
The pit viper, or South American rattlesnake, has many subspecies, all of which are highly venomous and potentially deadly. But the species found most often in Brazil, Crotalus Durissus Terrificus, possesses an extra, dangerous characteristic.
While most venomous snakes have a venom that attacks one specific part of their prey’s system, the Brazilian pit viper’s venom attacks two. It is a neurotoxic venom that can cause hypertension, shock, paralysis, blindness, renal, and respiratory failure. And it’s also a hemotoxic venom that causes bleeding. The incidences of bites from this snake being fatal if left untreated are high. Anyone bitten should seek emergency medical care.
Luckily this doubly venomous reptile is not aggressive. It only bites as a last resort and gives plenty of warning before it does so. If feeling threatened, a pit viper will rear back, hiss loudly, and sound its rattle giving predators plenty of opportunities to retreat. We advise you to take this warning seriously and give these creatures plenty of space.
What is the most dangerous animal in Brazil?
The most dangerous animal in Brazil is the poisonous dart frog. Their poison is so toxic that one frog has the potential to kill ten people.
What is the most dangerous snake in Brazil?
The pit viper is the most dangerous snake in Brazil because of its doubly effective venom, which is both hemotoxic and neurotoxic.
What is the most dangerous spider in Brazil?
The Brazilian wandering spider is the most dangerous spider in Brazil. It is a large, aggressive spider with a venomous bite that can be deadly if left untreated.
