You need energy to run, jump and even think. Where does it come from? Your food! And where did the energy in your food come from? Follow it back far enough, and you always reach the sun.
Key idea
Plants use sunlight to make food. Animals get energy by eating plants, or by eating animals that ate plants.
Why it works
Only plants (and a few tiny living things) can catch the sun's energy and store it in food. A rabbit eats grass and gets some of that energy. A fox eats the rabbit and gets some too. The energy passes along, from one living thing to the next.
Worked example: Let's think it through
A lizard lies on a warm rock in the sun. Is the sun giving it food energy?
- The sun warms the lizard, but warmth is not food.
- The lizard gets its energy from the insects it eats.
- The insects got theirs from plants, and the plants got it from the sun.
Answer: No. Its energy comes from its food, and that energy started with the sun.
Common mistake
Children often think the sun gives animals energy by warming them, or that animals make their own food like plants. Animal energy comes from food, and that energy came from the sun through plants.
For the grown-up. This connects Plants Make Their Own Food and Plant-Eaters, Meat-Eaters and Both. At a meal, pick one food and trace it back together: cheese came from milk, milk came from a cow, the cow ate grass, the grass used sunlight.