They contain concepts and vocabulary that should be understood when studying ecology. This means that all plants produce and provide food while animals get food, a process of eating and being eaten. In this example, as is often true, man is at the top of the food chain , while the small ocean animals and plants are considered to be at the bottom of the food chain . Even though animals at the top of a food chain do not directly eat plants or animals at the bottom of a food chain, those at the top rely on those at the bottom for the food that they ultimately supply to them. Among living things, plants are producers and exist at the bottom of the food chain.
Animals are consumers and usually occupy the middle or top of the food chain.
At different times, depending on who is eating what, most animals are both predator and prey. The big fish in the example above is a predator when it captures its prey, a small fish. However. when man, the ultimate predator, captures this same big fish, it becomes prey. The interlocking nature of food chains and food webs makes each part of the chain or web vital to the existence of the whole. If a single plant or animal that is part of a food chain or web is destroyed or removed, the entire chain or web can be destroyed.