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Year 4 Science

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Living Things Depend on Each Other

pond dipping

Close your eyes and imagine it's a cool summer day, and you're sitting by a little pond. Or, go pond dipping by watching this video about pond life before continuing with this activity. How many different living things are in this pond environment?

At a pond, you might see a frog or a newt, ducks or a heron. If you go pond dipping like James Chubb did in the video, maybe you will find an emperor dragonfly nymph or freshwater stick insects. You might see dragonflies skimming the surface of a pond. Hear a buzz? It could be a fly or a mosquito, since both of them can be found near a pond. If the water is clear and still, you might be able to see the fish that live underwater. If it's late in the day, you might notice some bats. If you were walking at the edge of this pond, what living things would you hear and see? They all share the pond environment.

And don't forget all the plants. Plants are living things, too. Think how many plants live near, and even in, a pond. Little plants grow right up to the pond's edge, and some plants grow underwater. There are also creatures, too small to see, living in the mud and in the water. All these living things depend on each other, and on the kind of world a pond setting provides. In other words, these plants and animals share the pond as their habitat.

In Year 2, we learnt about many different living things and their habitats - including the woodland, underground, desert and ocean habitats. In Year 3, we started learning about cycles in nature, like the cycle of the seasons. Let's see how some of the creatures living in and near the pond's freshwater habitat depend on one another. Green bushes grow at the edge of the pond. The bushes absorb light from the sunshine. Their roots take in water and nutrients from the soil near the pond. The bushes use sunlight, water and nutrients to grow big and healthy.

A tadpole swims up and nibbles on one of the roots. But watch out, little tadpole! What's that coming up behind you? It's a hungry fish. Chomp! The fish eats the tadpole in one gulp. A few months later the fish grows old and dies. Its body sinks to the bottom of the pond. Down under the water, tiny worms and bacteria - those creatures so tiny you can't see them - break down the dead fish's body as they use it for food. Nutrients from the decaying flesh and bones of the fish settle into the soil at the bottom of the pond. Those nutrients are absorbed by the roots of the bush growing at the water's edge. And so we're back where we started. This is one cycle in nature.

Look how many ways the living things of this pond depend on each other - and we haven't talked about how birds like herons catch fish to eat them, or how mammals like deer can come to drink water at the pond's edge! All these creatures, living together, are part of a cycle of nature.

Continue your pond explorations! You can watch reedbed wildlife at Leighton Moss with the webcam of the Royal Society for the Protection of Birds, or you can spy on beavers, swans and other animals with the webcams of the Wildfowl & Wetlands Trust. Or, perhaps you can go pond dipping yourself and make your own video of your adventure and what you find. You can upload your video online on YouTube or Vimeo and then email us at to let us know. We could feature a link to your video on our website!

This activity is adapted from What Your Year 4 Child Needs to Know, which can be purchased here. Click below to see related activities.

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science owl
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