Tossing Your Enemies Into Piranha-Infested Water Won’t Solve Your Problems

There is one person in particular that we can thank for the stomach-liquifying, nightmare-inducing terror piranhas are thought to cause, and that is Theodore Roosevelt, the 26^th US President.

On vacation, to find himself after the ego-blowing defeat to Woodrow Wilson in 1912, Roosevelt decided to go on an expedition in South America. He traveled down an “unexplored” (but not unexplored to the native population) “River of Doubt” – which does not sound like it would be a relaxing holiday at all. This river, which has now been renamed Roosevelt River, was in the depths of the Amazon basin.

The local people wanted to put on a show for Roosevelt and fellow travelers, and fishermen isolated a section of the river with nets and then spent weeks catching and dumping piranhas into this slice of water. When Roosevelt was on a cruise at this section, the cruise members were told that no one ever enters this part of the river and then proceeded to push an aging, sick cow into the section.

What the people on the boat witnessed was a feeding frenzy of the fish. Nowadays, it is suspected that these fish were purposefully starved and that was why they made very quick work of the cow. This resulted in the section of the river being bathed in red. A few moments later, so the story goes, a clean skeleton of the cow was retrieved.

This event left such an impression that Roosevelt wrote about it in his book, Through the Brazillian Wilderness: “They are the most ferocious fish in the world. Even the most formidable fish, the sharks or the barracudas, usually attack things smaller than themselves. But the piranhas habitually attack things much larger than themselves.”

But, how true is this statement from Roosevelt, and is there any scientific evidence to back it up?

What are piranhas?

There are more than 30 species of piranha – a freshwater fish that mainly lives in the rivers or lakes of South America. Piranhas have been around for a long time, there is fossil evidence that indicates their ancestors have been here for 25 million years, and that modern-day piranhas have been around for 1.8 million years.

They are characteristically known for their sharp, interlocking teeth on each jaw. Their bite force is amazingly strong; black piranhas even hold the Guinness World Record for the most powerful bite relative to body size. All the better to nibble you with, my dear.

Contrary to what you might expect, not all piranhas even eat meat. Depending on the species, some are omnivores and like to chow down on worms, fish, plant matter, and insects. Wimple piranhas like to chomp down on other fish’s scales.

But the one we are concerned with, the one most people are familiar with, is the red-bellied piranha. These bad boys like to form shoals of between 10-100 individuals. These are the ones most depicted in popular culture, but the reason for their pack like behavior is more to do with protection. Piranhas have many predators and researchers have found that shoals of these fish breathe faster when they are in smaller groups, which indicates that they are more anxious.

On the whole, most piranhas are known to be scavengers and while a few species may love blood, more often than not, they seek out prey that are the same size as them.

Do piranhas bite humans?

In the past, there have been bites that have been minor or more extreme, however, they are still very rare. The most common piranha injury in humans is normally a single fish biting only once. The bites normally result in a circular, crater-like wound.

Typically, when they do bite it is because people are bathing in dammed water or because they have been handled, disturbed when they are mating or when they are guarding eggs, or even when there has been starvation stress (as the cow in Roosevelt’s story found out).

Most of the time piranhas avoid contact with people, but if you ever fall into a river of piranhas, it may be best to calmly move out of the water with very limited splashing.

How often are people attacked by piranhas?

Being attacked by piranhas is a very rare occurrence, but it can still happen. In 2002, there was an outbreak of speckled or dark-banded piranha bites in the town of Santa Cruz of Conceição, in the main river that connected the dammed waters of the local neighborhood.

As people do in the hot summer, many people were swarming to the area to lounge about by the waterside and have a cooling dip in the river. In one particular time period of five weekends, there were 38 instances of piranha bites. Most of the bites were on the person’s lower limbs. The local authorities had to place warning signs, distribute pamphlets, and set up a care station to tackle the situation.

All the attacks were one bite per person, and most people got treatment at a nearby setup station. However, five patients had to be transported to a larger medical facility due to excessive bleeding, while one person had a toe amputated.

It is thought that most people were bitten because they waded through shallow waters and approached an egg clutch site.  

There have been cases where a person has been found dead with piranha bites, although, it is often unclear whether the person drowned before coming into contact with the piranhas. For example, in 2015, a 6-year-old girl was found dead in Maicuru River, Brazil, after a canoe had capsized during a storm. The flesh was stripped from her legs after being surrounded by a large shoal of piranhas, and it was unclear whether it was drowning or piranhas that caused the fatality.

In 2022, in Paraguay, the bodies of four swimmers were found in a short space of each other. The first, found dead in the Paraguay River, had chunks missing out of the body. In the same river, the second disappeared from view while bathing and his face and limbs showed some piranha bites. Then two other people were found dead In the Tebicuary River. It was thought that these incidences occurred due to the breeding season as the fish were protecting their eggs and young.

Overall, it is known that piranhas can nip at people, however, it is very rare. There is a greater chance that piranhas will be caught and made into a meal instead, as they are a delicacy and staple for many people.