Edit Ive been told these could be either Earthworm hatchlings, Potworms from Fungus Gnats or Jumping worms commonly found in potting soil. We are told most likely the Potworms from Fungus Gnats , We Artificial Plants & Trees Lifelike Greenery by Floralsilk How and When to Sow Wildflower Seeds BBC Gardeners World Magazine Custom Moss Pole Planter Pots Made From Recycled Materials Kanso Designs