They don't really need to see as they spend almost all their life underground. They have primitive eyes that can distinguish between light and dark - but that's about it.
Nothing,they are blind.
By making the soil moist and putting earthworms in it so it could fertilize.
Earthworms naturally aerate the soil which could otherwise become packed and dense.
Yes, soil is essential for earthworms as they burrow through it to create tunnels and extract nutrients. Earthworms rely on soil for food, shelter, and protection. Without soil, earthworms would struggle to survive.
Because earthworms eat just about every other organism in the soil.
they fertilize the soil
Earthworms cling to soil using their setae, which are tiny bristles located on their body. These setae help the earthworms move through the soil by gripping and anchoring onto the soil particles. This allows the earthworms to burrow efficiently and navigate through their environment.
The answer is that earthworms help to build soil and fertilize
Earthworms require oxygen to breathe, and when soil is saturated with water, there is not enough air present for the earthworms to survive. The excess water limits the movement of air in the soil, causing oxygen levels to drop and suffocating the earthworms.
Earthworms help decompose organic matter in compost heaps and in the soil.
they live in rachin soil
they add fertility to the soil