Question

Earth worms can: 

Harm the soil

loosen and aerate the soil

tighten the soil

destroy the farmers work​

Answer 1

Answer:

Thus Earthworms facilitate improving soil fertility and deposits on the surface. ... The micro-tunnels provide good root growth as they are lined with readily available nutrients and make it easier for roots to penetrate deep into the soil. They save the fertilizer cost.

Answer 2

Earthworms can loosen and aerate the soil

Additional information :

Due to this reason, earthworms are also said to be as farmer's friend as they even make it more fertile soil.