What are food chains and food webs?

Fish food chain
A food chain is a diagram that shows us how animals are linked by what they eat; in food webs we represent the links between animals who eat or are eaten by more than one kind of animal. We explain how children learn about food chains in the primary-school classroom in our guide for parents.

What is a food chain?

A food chain shows us how plants and animals within a habitat rely on each other for food. Food chains usually start with a green plant (a producer) which is eaten by an animal (a consumer), which is then eaten by another animal. The food chain is a single list which connects a producer with several different levels of consumers.

What is a food web?

Most plants and animals are part of more than one food chain. When a number of food chains in a specific habitat (a forest habitat, for example, or a desert habitat) are joined together we call them a food web.

How are children taught about food chains in primary school?

Within a habitat things interact with each other to form an ecosystem. As part of the ecosystem energy is passed from plants (which produce carbohydrates, like sugar, and protein) to the animals who eat the plants (and use the carbohydrates and proteins to build their bodies) and then on to the animals who feed on that animal. So a leaf provides food for a caterpillar, which is then eaten by a frog, which is then eaten by a snake and so on.

In a food chain diagram arrows point from the thing that is being eaten to the thing that is eating it. For example, this is a marine food chain:

In this food chain, primary producers are seaweed or phytoplankton. Primary consumers are the zooplankton, who are in turn eaten by secondary consumers such as small fish. They are eaten by tertiary consumers (larger fish), who are in turn consumed by quatenary consumers like sharks. We also talk about animals that eat other animals as predators.  Animals that get eaten by other animals are prey.

When are children taught about food chains in primary school?

In Year 1, children learn that there are various types of animals, including amphibians, fish, reptiles, birds and mammals. They also learn that carnivores eat meat, herbivores eat plants and omnivores eat both.

This provides a solid basis for the learning in Year 2, where children start to learn about the habitats where animals live. They then start to look at food chains, so they understand how the animals in a habitat are reliant on each other.

Children continue to learn about animal nutrition in Year 3

In Year 4 they continue their learning of habitats and learn about how changes to the environment can affect animals in different ways (for example: deforestation takes away habitats and therefore food from a variety of species). They go over their learning of food chains again, but this time incorporate learning about teeth and the digestive system, and how these differ in different animals.

Methods teachers use to teach food chains might include:

  • Giving children lots of pictures to cut out and then organise into a food chain. They may ask children to stick them in their books and then draw the arrow on themselves so that they understand the direction the arrows should go in.
  • Getting children to act out a food chain in front of the class; for example, one child might pretend to be a leaf, another might be a slug eating the leaf, then a third might be a bird eating the slug. 
  • Children may be asked to research their own food chains at home. They may be asked to look at books and on the Internet to see what they can find out about different animals.
  • Children may be given one particular animal, then asked if they can come up with their own food chain which includes this animal. This can be a good activity to do at the start of a unit to assess children’s existing knowledge or it might be completed at the end of the unit, to see how much they have learned.

Children's books about food chains

      

Food chains activities to try at home

Look through TheSchoolRun's Food chain Homework Gnome for ideas and tips, and try some of our food chain worksheets.