ScienceGrade 3

How Does Energy Move Through a Food Chain? Ecosystems for Kids

All energy in a food chain starts with the Sun; plants (producers) capture it.

Learning Objective

Students will trace how energy flows from the Sun through a food chain (producer → primary consumer → secondary consumer → decomposer), and explain that only a small fraction of energy passes to each next level (TEKS 3.9A, 3.9B).

What You'll Learn

Energy passes one direction along the chain: producer → herbivore → carnivore.
At each step, most energy is lost as heat and movement — only about 10% passes on
Decomposers (like fungi and worms) break down dead plants/animals and return
Removing one link (e.g. all the grasshoppers vanish) breaks the energy supply for

Words to Know

Producer: A living thing that makes its own food from sunlight.; Grass is a producer — it turns sunlight into food.
Consumer: A living thing that eats other living things to get energy.; A grasshopper eating grass is a consumer.
Decomposer: A living thing that breaks down dead plants and animals.; Worms and fungi are decomposers that make new soil.
Energy: The power something needs to move, grow, or stay alive.; Sunlight is the energy that starts the whole food chain.
Food chain: The path energy takes as one living thing eats another.; Grass → grasshopper → frog → snake → hawk is a food chain.