In the rain forest, primary consumers are generally the smallest on the food chain and include insects and small mammals, such as chipmunks, mice and squirrels. Primary consumers are found in terrestrial areas and in aquatic habitats, and they are generally located on the forest floor or in low levels of the canopy. In rivers, streams and other bodies of water running through the rain forest, primary consumers include fish such as salmon that feed on water organisms and insects.
Each rain forest has a basic food chain consisting of three levels of producers and three levels of consumers. Regardless of whether rain forests are temperate or tropical, this structure remains the same. In all rain forests, the primary consumers eat small insects, plants and shrubs. Their food sources are generally the organisms that are classified as primary producers — a group that includes ferns, mosses, mushrooms and other small plants. Primary consumers help to pollinate and populate native flora species, and they help to control insect populations by feeding on bugs, flies and other abundant species. These consumers, as the lowest on the food chain, also provide critical sources of food for secondary and tertiary consumers, giving them the nutrients and energy they need to make the rain forest ecosystem complete.