What your child learns
- Explain that almost all food energy starts with the sun.
- Sort living things into producers, consumers and decomposers.
- Read and draw food chains and food webs with arrows pointing the right way.
- Predict what happens to a food web when one living thing disappears.
NGSS 5-LS2-1 NGSS 5-PS3-1
Every living thing needs energy. A food chain shows how energy moves from one living thing to the next when something eats something else. Because animals eat more than one kind of food, real ecosystems are made of many linked chains, called a food web.
The three main roles
| Role | What it does | Examples |
|---|---|---|
| Producer | Makes its own food using sunlight | Grass, trees, algae |
| Consumer | Eats other living things for energy | Rabbits (herbivores), foxes (carnivores), bears (omnivores) |
| Decomposer | Breaks down dead things and returns nutrients to the soil | Mushrooms, bacteria, earthworms |
Example 1: A meadow food chain
Sun → grass → grasshopper → frog → snake → hawk
- Grass is the producer.
- The grasshopper is a primary consumer (it eats the plant).
- The frog is a secondary consumer, the snake a tertiary consumer, and the hawk the top predator.
The arrows mean "is eaten by". Energy flows the same way the arrows point.
Why food chains are short
At each step, most of the energy is used by the animal to move, grow and keep warm, and only a small part (roughly a tenth) is passed on. That is why there are many more plants than rabbits, and many more rabbits than foxes.
Example 2: A pond food web
Algae are eaten by tadpoles and small fish. Tadpoles are eaten by fish and herons. Fish are eaten by herons and turtles. If a disease wiped out the tadpoles, the fish would have less food, and herons would eat more fish, so the fish population could fall too. A change to one living thing ripples through the whole web.
Practice
- Is an oak tree a producer, consumer or decomposer?
- Put in order: owl, seeds, mouse.
- Which way should the arrow point between "rabbit" and "fox"?
- Name two decomposers.
- What is the original source of energy in almost every food chain?
- A bear eats berries and fish. Is it a herbivore, carnivore or omnivore?
- In the meadow chain above, what might happen to the grasshoppers if all the frogs disappeared?
Show answers
- Producer
- Seeds → mouse → owl
- From rabbit to fox (the fox eats the rabbit)
- Any two of: mushrooms and other fungi, bacteria, earthworms
- The sun
- Omnivore
- Grasshoppers would increase at first because fewer are eaten, and then they might eat so much grass that their food runs low.
Common mix-ups
- Arrows pointing backwards: say "is eaten by" out loud as you draw each arrow.
- Forgetting the sun: plants are producers because they capture the sun's energy. Start every chain with the sun.
- Thinking decomposers are not important: without them, dead plants and animals would pile up and soil would run out of nutrients.
Try it at home
Pick a habitat near you, such as a park, a garden or a pond. List 8 living things you might find there and draw arrows to make a food web. Which living thing has the most arrows? What would happen if it disappeared?
Watch The Water Cycle for Kids and Solar System for Kids, or browse all Grades 3–5 lessons.
Questions parents ask
What is the difference between a food chain and a food web?
A food chain shows one path of energy, like grass to rabbit to fox. A food web shows many connected food chains in the same ecosystem.
Which way do the arrows point in a food chain?
Arrows point in the direction the energy goes, from the food to the eater. So the arrow goes from grass to rabbit, meaning the rabbit eats the grass.
Why are decomposers important?
Decomposers such as fungi, bacteria and worms break down dead plants and animals and return nutrients to the soil, so new plants can grow.
