A consumer in science refers to an organism, typically an animal, that feeds on other animals or plants. The consumer is part of the food chain and is studied in the science field known as ecology.
In the natural ecosystem, there is a food chain or food web. At the bottom of the food chain are the producers, which are plants and vegetables. These producers get their energy from the sun and then they use that energy to make food through the process of photosynthesis. They then also make nutrients from that same energy. Next on the food chain are the consumers.
The consumers have three levels. The first level is the primary consumer. The primary consumer is also called a herbivore because they only eat the plants. An elk or a squirrel are both examples of primary consumers. The primary consumer will not eat other animals and only eats other plants and fruit. The secondary consumer is known as a carnivore as it eats only animals. The secondary consumers eat the primary consumers. An example of this might be a secondary consumer cat who eats a primary consumer mouse. In some of the various ecosystems, there is a third consumer called the tertiary consumer. These consumers eat both secondary and primary consumers. These consumers are omnivores. Humans are tertiary consumers.