  A food chain is a linear network of links, often starting with decomposers such as microbes, fungi, maggots or earthworms. Decomposers break down organic materials into basic organic and inorganic compounds made up of nitrogen, carbon, calcium, phosphorus, and other chemical elements, which plants and other producers use for growth.
The next level up is producers, which take the nutrients released by the decomposers and turn them into plant material using energy from the Sun. These are eaten by one or more levels of consumers, ending at an apex consumer, a top level consumer that has no predators. Most producers use photosynthesis to create food for other organisms, the primary consumers. These are usually herbivores, but may also be omnivores, animals that can eat both plants and other animals. Secondary consumers, which make up the next level, are carnivores or omnivores that prey on primary consumers. Tertiary consumers are very often large carnivores that prey on secondary consumers Here are some examples of some food chains: 
 Food Webs A food web consists of all the food chains in a single ecosystem. It is a complex network of interconnecting and overlapping food chains showing feeding relationships within a community. A single food chain shows how energy from food is transferred from one organism to another, while a food web illustrates how food chains interconnect in an ecosystem. Food webs also demonstrate that most organisms consume or are consumed by more than one species, which food chains often do not show. Large carnivores and omnivores may also eat primary consumers if given the opportunity. For example, a wolf might eat mice. They may also eat producers, where for example a bear might eat berries. In addition, many organisms within a food web may be part of several food chains within that ecosystem. For example, squirrels eat a variety of foods, including nuts, fruits, seeds, fungi, and insects. Similarly, squirrels are prey for not only foxes, but also hawks, owls, and other predators. |