What is common to earthworm, mushroom, soil mites and dung beetlein an ecosystem. 

Explanation

### Step-by-Step Solution:

1. **Identify the Organisms**: The question asks about the commonality between earthworms, mushrooms, soil mites, and dung beetles in an ecosystem.

2. **Understand Their Roles**:
- **Earthworms**: These organisms are found in the soil and play a crucial role in decomposition. They break down organic matter, enriching the soil.
- **Mushrooms**: As fungi, mushrooms are saprophytes that feed on dead and decaying organic material, contributing to the decomposition process.
- **Soil Mites**: These tiny creatures also inhabit the soil and assist in breaking down organic matter, further aiding in decomposition.
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