A rabbit eats grass. A fox eats the rabbit. The energy in the fox's dinner came, in the end, from the Sun.
Key idea
Producers (plants and algae) make food from sunlight. Consumers eat other living things: herbivores eat plants, carnivores eat animals, omnivores eat both. Decomposers (mushrooms, bacteria, worms help too) break down dead plants and animals and return their minerals to the soil.
Most animals eat more than one thing, and are eaten by more than one thing. When we draw all the chains together, they make a food web.
Why it works
If the rabbits all disappeared, the foxes and hawks would have less to eat, and the grass might grow taller. A change in one part of a web changes the others.
Worked example: Read the arrows
In the chain seeds → mouse → owl, what does the owl eat?
- The arrow points from the food to the eater.
- The arrow into the owl comes from the mouse.
Answer: The mouse.
Common mistake
Reading the arrows backward. "Grass → rabbit" means energy goes from the grass to the rabbit: the rabbit eats the grass.
Try it at home
- Write down everything you ate yesterday.
- For each food, trace it back to a producer. (Cheese → cow → grass. Bread → wheat.) Does every chain start with a plant?
Going further. Run a whole ecosystem in Predators and Prey, and see Food Webs in Life Science.