Somewhere in Brazil, people are feeding carnivorous fish by throwing big pieces of meat in the water. 

As soon as their lunch hits the water, the fish go wild and attack the meat as if it were live prey. The whole river starts to swarm with the piranhas attracted by the taste of fresh blood. 
It's quite a terrifying sight for us humans, especially for those of us who enjoy going for a swim every once in a while. You would not want to stick as much as a toe in that river! Have you ever seen anything like it? Let us know in the comment section!