Actually, the neatest display I ever saw was the one at the New York State Aquarium on Coney Island. There, they had this huge monster tank with about ten full grown, eatin' size piranha in it, and nothing but wall to wall neons and cardinals. I mean, there was a neon in every space, none of them packed and schooling, but evenly spaced out in the tank as if one neon per cubic inch of water, and the piranha swam through them as gentle as you please...They really are a quite harmless fish. The natives of SA fear freshwater stingrays and electric eels more than piranha, which they catch and eat regularly.
Those piranha were so fat and well fed, that to chase after a neon would be completely pointless. Piranha are also somewhat veggie eaters as well, eating nuts and fruits that fall into the water when the rivers flood the forests of their native Amazon. They really only become viciously carnivorous during the dry season when food is scarse, or when ignorant people think it is macho to have killer piranha.
~~Colesea