Organisms like bacteria and fungi that decompose are called decomposers.

Here's why:

* Decomposers break down dead organic matter: They feed on dead plants and animals, breaking them down into simpler substances.

* They play a vital role in nutrient cycling: This process releases nutrients back into the soil, making them available for other organisms to use.

* They are essential for ecosystem balance: Without decomposers, the Earth would be piled high with dead organisms, and essential nutrients would be locked up.

Let me know if you have any other questions!