The Piranhas are not as aggressive as we thought they were, making them the 'most terrifying planet on the planet'.

Piranha, the notorious fish in the Amazon River (Brazil) is known for its sharp teeth, extremely thirsty and crowded. They become the terror of many animals and humans. Hollywood filmmakers have created many of these scary fish horror movies, in common with the ability to clean bones of any living organism that falls into their territory.

The first to witness the Piranha's aggression was Theodore Roosevelt, when he and his team conducted an expedition down the "mysterious river" deep in the Amazon basin in 1912.

The trip started with 19 people, for many reasons such as illness, lack of food, drowning . only 16 people returned. Roosevelt himself also suffered from a serious foot injury, even showing signs of infection.

For Roosevelt, this was an unhappy but meaningful trip because he was the first North American politician to visit the Amazon. Here, he and his team were "entertained" by many native fishermen.

According to Herbert R. Axelrod, a tropical fish researcher, the Amazon fishermen used a net of hundreds of starved piranhas into a 90m wide river area. After that, they pushed a sick old cow into the river. Roosevelt had witnessed the extremely scary scene, hundreds of fishes waving themselves at the bad cow. Just over 10 minutes later, the cow was only a white skeleton.

Roosevelt was obsessed with the scene and he later described piranhas as the world's most aggressive fish in the book "Through the Brazilian Wilderness". He said: ' Even sharks often hunt only smaller than them. Piranhas are ready to attack any prey that is larger than them many times . "

The sight of Roosevelt is real, and his descriptions in his book have made people obsessed with the fear of piranha for a long time. However, the researchers later revealed a startling fact, such fast-growing bulls of piranhas were humans. Those encircled piranhas are very aggressive and can attack prey very quickly because they are starved.

In fact, piranhas are carnivorous, their food varies from animals, insects, fish to their own. However, the human and animal skeletons of this fish have all died before. They attacked living creatures but they were mainly weak and slow old people who came to drink water.

A 2003 study found that there were very few cases of people being eaten by piranhas in history, at least 3 of them died before being attacked.

Unlike many people's thoughts, piranhas do not really attack anything. If any creature unfortunately fell into the water, they only took a bite, not biting continuously. And these victims were only significantly scratched and not killed.

Piranha fish do not consider human movement as a goal so even if you swim across a river with this fish, you can still ensure your safety.

However, it is true that cases of humans suffering from Piranha 'asking for' a few fingers or legs in encounters are real, and the rate is increasing. The reason is that more and more dams appear on the Amazon River, this is not only the perfect environment for piranhas to come and reproduce, but also a favorite place for people to swim, making the encounter rate between people and fish also increased.