Which natural agent helps to loosen and aerate the soil? 

Earthworms are natural agents that play a vital role in improving soil health. 

They create extensive channels and burrows in the soil, which helps to loosen and aerate it. 

This improves soil drainage and allows water and air to move freely through the soil. 

Soils with earthworms have been found to drain up to 10 times faster than soils without them. 

Additionally, earthworms help to break down organic matter in the soil, releasing important nutrients that are necessary for plant growth.