Plants and animals are living things. They come to life, grow and change. Every living thing dies at some time. When a living thing dies, its body stops working. A body that has died does not start working again. Dead is forever. So what happens to all those bodies? A crew goes to work, and it never takes a day off.

Dead plants and animals are food for decomposers, such as bacteria, fungi and earthworms. Decomposers break dead things down into nutrients that go back into the soil, where plants can use them again. Decomposers are nature's recyclers. Without them, waste would pile up.

The smallest workers are bacteria. Bacteria are tiny living things. The ones that live on dead material break it down into nutrients that go back to the soil. Living things are made of cells, and some living things are made of only one cell.

Fungi are the crew's chemists. Fungi cannot make their own food. They release enzymes that break down dead plants and animals. Fungi can break down tough parts of wood and plants, such as lignin, chitin and cellulose. Fungi feast on a decaying tree, and fungi and bacteria help break down lignin, the tough stuff in wood.

Then come the earthworms. Earthworms eat dead plants and animals, and they loosen the soil as they burrow. Earthworm droppings, called casts, are rich in nitrogen, phosphorus and potassium, which help plants grow. When plant and animal matter decays, it forms humus. Humus is dark, nitrogen-rich soil matter that holds nutrients for plants.

Millipedes, sow bugs and fly larvae also help break down dead material, and so do many other small arthropods. Bigger scavengers do their part too. Scavengers such as vultures and sea eagles find dead animals quickly and eat them. Between the big eaters and the small ones, little is wasted.

The crew also works in the deep sea. When a whale dies and sinks to the sea floor, its body feeds deep-sea animals. This is called a whale fall. Scavengers such as sharks, hagfish, rattails and crabs eat the flesh off the bones. They eat the soft parts in a matter of months, and then different animals arrive. Bone-eating worms make an acid that dissolves the hard outer layer of whale bone. A whale fall is an oasis of food on a deep-sea floor where food is often hard to find. In deep water, a skeleton can feed animals for years, even decades.

Rivers get a delivery too. After Pacific salmon lay their eggs, they die. Their bodies feed scavengers or rot, adding nutrients to the stream.

Not every body is cleaned away. Most dead plants and animals decay or get eaten, so only some become fossils. A fossil often starts when a dead plant or animal is buried quickly by mud, sand or ash. Soft parts rot away and hard parts such as bones, teeth and shells are left behind. Over time the mud and sand harden into rock, and water full of minerals soaks into the remains and can turn bones to stone.

People and families believe different things about death. Ask yours. The facts here are about the bodies of plants and animals. If a death in your life makes you sad or full of questions, talk to a grown-up you trust, such as a parent, a teacher or a school counselor. They are there to listen.

Words to know

• decomposers: dead-matter eaters
• bacteria: tiny living things
• enzymes: breakdown chemicals
• humus: dark soil matter
• scavengers: leftover eaters