All living things need to feed to get the energy to grow, move, and reproduce. But what do living things feed on? Smaller insects feed on green plants, and larger animals feed on smaller ones and so on. This feeding relationship in an ecosystem is called a food chain. Food chains are usually in a sequence, with an arrow used to show the flow of energy.
Below are some living things that can fit into a food chain.
Here is an example of another food chain in the Tundra. Click here.
A food chain is not the same as a food web.
A food web is a network of many food chains and more complex.
See the food web illustration below—you can pick out a basic food chain from the web, Green plants — Grasshopper — Frog — Bird — Hawk
In the diagram above, the arrows show the direction of energy flow. It points to the animal doing the eating.
Energy is transferred along food chains from one level to the next. Some of the energy is used up in growth, reproduction repair, movement, and other ways, and not made available to the next level.
Shorter food chains retain more energy than longer chains. Used up energy is absorbed by the environment.