How does an earthworm move?

Explanation

### Step-by-Step Solution:

1. **Identify the Earthworm**: An earthworm is an invertebrate animal that resembles a long, segmented worm.

2. **Examine the Structure**: The underside of an earthworm has many tiny projections known as bristles or "setae."

3. **Function of Bristles**: These bristles provide friction, allowing the earthworm to grip the soil and prevent slipping.

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