Mineral salts are recycled in the ecosystem. All food chains start with a producer. They get their energy by eating other living things. Primary consumers eat plants, we also call them herbivores. Some herbivores graze on plants and others browse.
Carnivores are secondary consumers, they eat other animals.
A thrush eating a snail is an example of a carnivore, as is a lion eating a zebra. Some animals can choose between being a herbivore and being a carnivore, they eat both animals and plants and we call them omnivores, they are either primary or secondary consumers. Scavengers are also consumers, but they wait for their prey to die first. A food chain is a very simple diagram to show how energy flows through an ecosystem. This food chain shows energy from the sun is used by grass, the cow gets its energy by eating the grass, and then we get energy by eating the cow or drinking its milk.