Piranhas are full of triangular teeth, sharper than razors. It not only attacks animals in the water crazily, but also jumps out of the water to attack large waterfowl. Piranhas are particularly sensitive to blood. A little blood and a little smell of blood will make them flock to them. It can be said that any river with piranhas has become a terrible river. Because, if land animals or people unfortunately fall into such a river, in a few minutes, the large animals that were alive just now will suddenly become a skeleton. They even attacked their own kind. If the piranha can't get free after swallowing the bait on the hook, the vicious and greedy companion will soon eat all its bones.