ProducerA living thing that makes its own food, here from sunlight. Producers are the first level of every food chain. Also called an autotroph.
Primary consumerAn animal that eats producers. Primary consumers are the second level of a food chain.
Secondary consumerAn animal that eats primary consumers. It is the third level of a food chain.
Tertiary consumerAn animal that eats secondary consumers. It is the fourth level of a food chain.
Apex predatorThe predator at the top of a food chain. It has no predators of its own. Also called a top predator.
Sun, arrows and decomposers 3
SunThe source of energy for this food chain. Grass makes its own food from sunlight.
Energy flow (arrow)Each arrow shows energy passing from a living thing to its eater. The arrow points at the eater.
DecomposerA living thing that breaks down dead plants and animals. That returns their nutrients to the soil. A fungus or a bacterium is one.
Who eats what 3
HerbivoreAn animal that eats only plants. In this web the grasshopper and the rabbit are herbivores, so either one is right.
OmnivoreAn animal that eats both plants and animals. Here the rat eats grass seeds and grasshoppers, and the fox eats berries, rats and rabbits.
CarnivoreAn animal that eats other animals. In this web the snake and the hawk are carnivores, so either one is right.
How this list was compiled: Every name and detail line was checked on 2026-09-30 against (1) OpenStax Biology 2e, 46.1 Ecology of Ecosystems, https://openstax.org/books/biology-2e/pages/46-1-ecology-of-ecosystems; (2) OpenStax Biology 2e, 46.2 Energy Flow through Ecosystems, https://openstax.org/books/biology-2e/pages/46-2-energy-flow-through-ecosystems; (3) National Geographic Education, Food Chain, https://education.nationalgeographic.org/resource/food-chain/; (4) NOAA Education, Aquatic food webs, https://www.noaa.gov/education/resource-collections/marine-life/aquatic-food-webs; (5) Wikipedia, Food chain and Trophic level; (6) Wikipedia, Red fox, Red-tailed hawk, Brown rat and Grasshopper, for who eats what. A name is asked only where two of them use it. The hints and detail lines are in our own words. Licence: own work
The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work
How it works
The parts of a food chain, shown on five living things from a grassland: grass, a grasshopper, a rat, a snake and a hawk. A second view adds a rabbit and a fox to make a food web.
Read the full guide
Read the arrows
Each arrow points from a living thing to the one that eats it, the way the energy goes. Grass is the producer. The grasshopper that eats it is the primary consumer, the rat is the secondary consumer, the snake the tertiary consumer and the hawk the apex predator. Fungi and bacteria, the decomposers, break down whatever dies.
Label the food web
In the second view, find a herbivore, an omnivore and a carnivore. Look at the arrows that reach each animal: from plants only, from animals only, or from both.
The arrow points at the eater, not at the food: from the grass to the grasshopper.
One animal can have two roles: the rat is a secondary consumer eating a grasshopper and a primary consumer eating grass seeds.
Questions and answers
What are the parts of a food chain?
A producer, which makes its own food; consumers, which eat other living things (primary, secondary and tertiary); and decomposers, which break down what dies. The sun supplies the energy.
What is the difference between a food chain and a food web?
A food chain is one path that energy takes, from a producer to a top predator. A food web is all the overlapping food chains in one place, so most living things have more than one arrow.
Which way do the arrows point in a food chain?
From the living thing that is eaten to the one that eats it. The arrows show the direction energy flows.
What do decomposers do in a food chain?
Decomposers such as fungi and bacteria break down dead plants and animals. That returns nutrients to the soil, where producers use them again.