No, piranha will not bite you. Although they are often associated with being aggressive, piranha are actually quite shy and will only bite if they feel threatened. If you do find yourself in the water with piranha, it is best to stay calm and avoid making any sudden movements.it's a common misconception that piranhas are aggressive and will bite humans. In reality, they are shy creatures that mostly feed on smaller fish. There have been very few reports of piranhas biting humans, and most of those have been due to humans feeding them or trying to capture them. So, unless you're planning on feeding a piranha or sticking your hand in their tank, you're unlikely to get bitten.