Can Piranhas Actually Eat Humans? 5 Facts and 3 Myths

Pygocentrus nattereri. Piranha closeup in the aquarium
© Grigorii Pisotsckii/

Written by Patrick MacFarland

Published: April 10, 2024

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Nature is a beautiful thing. There is a world of plants and trees that give humans and animals life. There is also the world of animals. Creatures have roamed the Earth for millions of years, some of them are extinct and some of them are still on this planet today. There are very bizarre animals in this world. Scientists discover new species of animals every year. These new species have confounded us when we first knew of their existence. There are animals out there that blow our minds. One such animal is the piranha. The piranha is an omnivorous fish that mainly lives in the fresh waters of South America. The question remains, can piranhas actually eat humans? Let’s take a look at the five facts and three myths about these interesting and fascinating fish.

Myth #3

Piranha of the Amazon River

The 26th President Theodore Roosevelt is the main culprit in creating a bad reputation for piranhas.

©kata716/iStock / Getty Images Plus via Getty Images

Myth: Piranhas will eat animals much larger (such as a cow) than themselves in seconds. This is 100% false. However, all the movies have made piranhas into these evil creatures that eat anything, it all started with President Theodore Roosevelt. Roosevelt was an outdoors lover and he went exploring in South America in 1913. He wrote a best-selling book about his travels that was published in a book called Through the Brazilian Wilderness in 1914. There, he described piranhas as ferocious creatures that can bite a finger off a human and eat large animals rapidly.

Myth #2

Piranha (Colossoma macropomum) in an aquarium on a green background

Piranhas are misunderstood creatures that have been characterized as deadly.

©Andrei Armiagov/

Myth: They will attack randomly and in packs. Unfortunately, piranhas are one of the most misunderstood fish on this planet. Movies have sensationalized the piranha’s behavior with other animals and humans. Piranhas usually keep to themselves and won’t really attack in packs. Interestingly enough, piranhas are omnivores that have eaten plants and seeds, as well as other insects, fish, and worms.

Myth #1

Amazon Black Piranha teeth

©The Jungle Explorer/

Myth: Piranhas can eat humans. This is absolutely not true. The movies have created this flabbergasting misconception about piranhas. Of course, piranha attacks have happened in the past, but usually, the human will end up with several bites from the fish. So, you won’t die from a piranha eating you. However, be careful when approaching a piranha. It is important to note that piranhas are attracted to blood, splashing, and noise, so keep that in mind when traversing the Amazon.

Fact #5

Red-bellied piranha Pygocentrus nattereri or Red piranha in their habitat.

Piranhas can grow up to 14 inches long, whereas the red-bellied piranhas can grow to 20 inches long.

©Tatiana Belova/

Piranhas are known to bark. Yes, you read that right. Scientists have discovered that red-bellied piranhas make “calls” that are quite similar to barks. Usually, these barks are done as a protective measure against other fish piranhas encounters.

Fact #4

Piranhas should be kept alone or with a few other piranhas because they are known to be aggressive when there is a lot of fish.

©Paulo Juntas / Creative Commons - Original

Over the past few years, piranhas have been a very popular pet to keep in an aquarium. The red-bellied piranha is the most common species of piranha that people keep in aquariums. Even though keeping piranhas as pets is fine in some jurisdictions, they are illegal in several parts of the United States, as well as the Philippines where people can face up to four years in jail if caught.

Fact #3

big piranha fish swimming

Piranhas were discovered to be living in Bangladesh’s Kaptai Lake.

©Jirik V/

Although piranhas are omnivorous fish, it is known that they do eat each other sometimes. piranhas are in a way, cannibals. Usually, many piranhas eat several grams per day, however, when those food sources are low where they are, scientists have discovered that piranhas have eaten a part of a fellow piranha. The most fascinating part about this is that sometimes the Piranhas could be dead but sometimes they could also be alive.

Fact #2

What Do Piranhas Eat - Piranha Teeth

The number of species of piranhas is not known but can range from 30 to 60.


There are various species of piranhas and the largest one can actually bite with a force of 72 pounds. That is because it has strong teeth. The translation of piranha is “tooth fish” in the Tupi language. They have a total of 10, 4-millimeter teeth on each jaw. The piranhas usually shed their teeth, in sections, throughout their lifetime.

Fact #1

Sunset, Amazon

The piranha’s name comes from the Tupi people of South America and their language.

©12MN/iStock via Getty Images

Piranhas are fish that roam the fresh waters of South America. They are usually found in the Amazon River along with other fish. They are also found in the Amazon basin — the surrounding waterways, lakes, and rivers. Piranhas will most likely stay in one environment and don’t migrate to other parts of the river or lakes. Lastly, piranhas have lived in these waters for millions of years.

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About the Author

Patrick Macfarland is a writer at A-Z Animals primarily covering travel, geography, and history. Patrick has been writing for more than 10 years. In the past, he has been a teacher and a political candidate. He holds a Bachelor's Degree in Political Science from SDSU and a Master's Degree in European Union Studies from CIFE. From San Diego, California, Patrick loves to travel and try new recipes to cook.

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