A food chain shows the feeding relationship between different organisms in a particular environment and/or habitat. Plants are at the bottom of a food chain because they are producers that make their food from a process called photosynthesis . Organisms that can make their own food are called producers. Consumers are animals that eat the products of producers or other animals. The animal that eats the producer is called the primary consumer and it gains the most amount of energy. The animal that eats the primary consumer is called a secondary consumer which in the primary consumer's energy which is transferred becomes lower due to the primary consumer consuming some energy. The animal that eats the secondary consumer is called a tertiary consumer and so on to fourth, fifth, etc. The direction of arrows between the organisms shows who eats what and what gets eaten by what.