Those who feed on secondary consumers are tertiary consumers. In the figure above the snake acts as a secondary consumer and the hawk as a tertiary consumer. Some organisms, like the squirrel are at different levels. Consumers are also classified depending on what they eat. Herbivores are those that eat only plants or plant products.
Example are grasshoppers, mice, rabbits, deer, beavers, moose, cows, sheep, goats and groundhogs.
Carnivores, on the other hand, are those that eat only other animals. Examples of carnivores are foxes, frogs, snakes, hawks, and spiders. They eat frogs and lizards as well as fruits, flowers, and leaves. The last word that is worth mentioning in this section is trophic level, which corresponds to the different levels or steps in the food chain. In other words, the producers, the consumers, and the decomposers are the main trophic levels.