So awhile back I found lots of earthworm in a sack of plant. What did I do about it? I distributed the earthworms into other sacks of plants/plants. Why did I do this? Because earthworm helps in breaking organic matter in the soil which makes it easier for the plants to take up nutrients that they need.
They also help with aeration of the soil which helps in constantly loosing up the soil for air to get in and not making the soil water logged.
After the earth worm feeds on organic matter, their poo also adds more nutrition (phosphorus,nitrogen & good bacteria) to the plants.
Seeing earthworms in a soil is also a good indication that the soil is very fertile. Earthworms are important in gardening & one of soil/plant best friends.