How is setae structure earthworms?

Setae are small, bristle-like structures found on the body segments of earthworms. They are made of chitin and assist in locomotion by anchoring the worm to the soil as it moves. When the earthworm contracts its muscles, the setae extend to grip the ground, allowing it to push against the soil and navigate through it effectively. This adaptation plays a crucial role in the earthworm's ability to burrow and maintain its position in the substrate.