Piranhas live in enormous packs,or shoals.they spend most ofmtime hunting for food.Rivers are their primary habitat although,as a result of massive floding,they may occasionally find their way into lakes.but it is thought that they are unableto breed outhide of rivers. Pirnhar have voracious appetites, and they seek river lo cations that have plentiful fish supplies. Ther are foundin any well-stocked river within their natural habitat.