A leaf falls to the ground. It does not stay a leaf for long. Fungi and bacteria get to work when a plant dies. They are decomposers.

Fungi, like mushrooms and mould, are not plants. They cannot make their own food from sunlight.

Fungi are not the only helpers. Snails, beetles and worms help break down dead plants too.

Without these helpers, dead leaves would pile up on the ground. Dead wood would pile up too.

They turn dead things back into food for new plants. Rot has a job to do.

These helpers work best when it is warm and wet. Cold slows down the tiny living things that spoil food.

That is why we keep food in the fridge. But cold only slows mould. It does not stop it.

Mould can still grow on forgotten food in a fridge. Cold slows it down, but it does not stop it.

Fruit and vegetable scraps can go in a compost pile. So can dry leaves. Compost is dark and smells like fresh soil.

When things rot, nutrients go back into the soil. Living plants use them to grow. Then new plants can grow.

Words to know

• fungi: mould, mushrooms
• decomposers: break things down
• compost: dark soil
• mould: a fungus