Simple food chains: who eats whom
Aprende
All living things need food. Animals look for it: some eat plants and others eat other animals. Plants and algae do not eat: they make their food using sunlight.
A food chain says who eats whom. It always starts with a plant or an alga, because they make the food. Then come the animals, one after another. Each living thing in the chain is a link.
A chain with four links The arrow goes from the one that is eaten to the one that eats it. It points to the one that eats. It is read like this: the grass is eaten by the rabbit, and the rabbit is eaten by the eagle. It is not read “eats”.
The arrow points to the one that eats The animal that hunts another animal is the predator. The hunted animal is the prey. An animal can be both: the frog hunts the grasshopper, and the snake hunts the frog.
The frog is a predator and also prey There are food chains in all ecosystems: in the meadow, in the vegetable patch, in a lake and also in the sea. An animal usually eats different things. A chain only shows one path.
A food chain in the sea
Worked examples
Ejemplo 1
Julie looks at a meadow. She sees grass, a grasshopper and a frog. The grasshopper eats grass and the frog eats grasshoppers. How does she draw the food chain?
- It starts with the grass, which is a plant.
- The grasshopper eats grass: the arrow goes from the grass to the grasshopper.
- The frog eats grasshoppers: the arrow goes from the grasshopper to the frog.
The chain is grass → grasshopper → frog. The arrows point to the ones that eat.
¡Ojo! Many children draw the arrow towards what is eaten: grasshopper → grass.
Ejemplo 2
Tony sees a cat hunting mice in the neighbourhood. The mice eat wheat. What food chain do they form? What does it start with?
- Wheat is a plant: the chain starts with it.
- The mouse eats wheat: the arrow goes from the wheat to the mouse.
- The cat eats mice: the arrow goes from the mouse to the cat.
The chain is wheat → mouse → cat. It starts with the plant, not with the cat.
¡Ojo! Many children start with the cat, because it is the biggest.
Ejemplo 3
Ellie sees a lettuce, a snail and a hedgehog in her vegetable patch. The snail eats lettuce and the hedgehog eats snails. Which is the predator and which is the prey?
- The chain is lettuce → snail → hedgehog.
- The hedgehog hunts the snail: the hedgehog is the predator.
- The snail is the hedgehog’s prey.
The hedgehog is the predator and the snail is its prey.
¡Ojo! Many children think the prey is the one that hunts.
Un reto para pensar
Look at a garden, a playground or a park. Find a small animal, such as an ant or a snail, and notice what it eats. Draw a food chain of three living things with their arrows. Look without touching or bothering the animals.
Practica
Rondas de 10 preguntas. Elige el nivel: