Not only these nasty little fish are vicious, but scientists have discovered that those bloody piranhas can talk to each other. They use three sounds, each of them meaning a new different thing.
One of the sounds is a bark used to intimidate rivals. The other two were drumming songs produced when they attack each other. The discovery is part of a larger study to learn the behaviour of fish according to the sounds they produce, said the scientist leading the research, Eric Parmentier:
Eventually, if we understand the behaviour that's associated with the sounds, we might be able to listen to the sea and explain to fishermen: 'Now's not the best time to start fishing'.