How does an earthworm fix parts of its body to the ground?

Explanation

**Step-by-Step Solution:**

1. **Understanding the Earthworm's Body Structure**: The earthworm has a long, cylindrical body that is divided into segments. Each segment plays a role in its movement and stability.

2. **Identifying the Projections**: On the underside of the earthworm's body, there are tiny projections. These projections are crucial for the earthworm's ability to fix itself to the ground.

3. **Recognizing the Function of Bristles**: These tiny projections are known as "setae" (or ceta). They are small bristle-like structures that help the earthworm grip the soil.

...