Black Piranha especially.If a Piranha fish dies other fish will feed on it. (Video: Piranha 3D/Dimension Films) 7. Most piranha attacks on humans only result in minor injuries, typically to the feet or hands, but they are occasionally more serious and very rarely can be fatal. They however do not attack people as they think that they are predators and will avoid swimming towards people since it is a shy fish.Aggression is triggered when they are threatened or hungry evidence of a lack of food sources might be more likely to precipitate an attack.Most likely to be Red Bellied or Black Piranha as well, as these are known to be the most aggressive of the Piranha species.The Amazon basin is home to about 20 million people spread all over 8 countries. Also, Piranhas can smell a drop of blood in 200 liters of water.

This is when they become more aggressive. If an animal is severe sick or weak the fish can however attack the animal. These bites do not cause fatal threats to a person, as they are easily treated by visiting a doctor or the simple dressing of the wound. The Piranha will however show signs of cannibalism when there is scarcity of food, especially during the dry seasons in the Amazon region.There is such a thing as a Piranha feeding frenzy though.

During frenzies, the fish bite the animal in a large group and the water might turn red as the flesh of the animal is stripped. If on the first bite, there is sign of life, then the school can quickly disperse with as little risk as possible.If you fall into the water by becoming unconscious, you might be attacked by the Piranha fish but they will not attack you if you do not feel like you are weak. Thus blood in the water is a potential target for a meal. The Piranha fish is omnivorous, and apart from eating plants they will feed on weak and dead animals.

In Suriname there was an incident of a girl who had been bitten by Piranha fish, Jan disputed that the fish had killed the girl as he said that the media had exaggerated the news.So mostly Piranha are wary of humans in the water, as a precaution against real predators, but hypothetically several conditions would have to be metThe Piranha would have to be very hungry to risk itYou would have to be threatening the Piranha for it to see a bite as self defenceFor an attack to happen you would have to be incapacitated or unconsciousPiranha attacks happen when the prey is easily attacked or vulnerable. Piranha will quite happily attack while humans are in the water

With humans, it is most likely they were attacked after death by some other cause. There are a lot of incidences where humans are attacked but not as a sustained attack to kill. The Piranha bites are however limited to bites on the toes and the hands which do not cause adverse injuries on an individual.
One fish will bite the dead animal in a first strike to test the prey. Some Piranhas are exclusively herbivores while most of them are omnivorous in nature. Unlike most fish, Piranha have a strong parental instinct, and they will protect their young ones till they are capable of defending themselves. Fish experts say that they are timid and shy, but the Black Piranha and the Red-Bellied Piranha are the most aggressive.

Ironically the Piranha is more scared of you in the water than the other way around. Avoid swimming in Piranha infested water when the water is very low as you might be risking being bitten by the fish.The fish is sensitive to triggers, and as such is sensitive to the smell of blood in the water.The smell of blood would be an indication of an injured animal which the fish could prey on.