How do earthworms avoid loss of water from their gas exchange surface during unfavouable condition?

Earthworms have a specialized skin that is covered in a thin layer of mucous which helps to keep their gas exchange surface moist. This mucous layer acts as a barrier to prevent water loss through evaporation. Additionally, earthworms can retract into their burrows during unfavorable conditions to reduce exposure to dry air and conserve moisture. Finally, earthworms have a well-developed excretory system that helps regulate their internal water balance, allowing them to survive in a variety of environmental conditions.