The primitive food chain is mutually exclusive, so that different species can continue to survive in nature, piranhas have a nemesis even if they are fierce.
In the wild, wolves are pack animals, and by living in packs they stand at the top of the food chain, but despite this, they face daily threats
The world's largest frogs are carnivores, but when these giant frogs were tadpoles, they were super picky eaters and only ate a water plant that was a specialty of local waters
