Mini wormery


Learn where a worm likes to live and understand their importance for healthy soil and plants.

  • Estimated time: 30 minutes
  • Location: Outdoors
  • School term: All year round
  • Level of experience: No experience needed
  • Subject(s): Science

Learning objectives

  • Understand the role of worms in the process of decomposition

Essential background information



Cut the top off the bottles if pupils are too young to do this. 
Use a sharp pencil to pierce a hole near top of bottle to make cutting easier.


  • 2 litre clear, plastic bottles 
  • Safety scissors
  • Compost, soil or a mixture of both
  • Sharp sand
  • A few worms per bottle
  • Water to dampen layers
  • Worm food – grated carrot, vegetable peelings, dead leaves or shredded newspaper

Step by step

  1. Fill the bottle with alternating layers of sand, soil, and compost. Spray each layer with water so that it is damp.
  2. Cut the top quarter off your plastic bottle to make a lid. Make a slit in the side of the lid so that the top can close over the bottom part.
  3. Collect some worms from the garden. Look in the compost heap, under stones in damp places or dig a hole to find them.
  4. Add a few worms to the top of the bottle and watch them burrow down. Then add the ‘food’ to the top. Remember to wash your hands well after handling worms and compost.
  5. Wrap the black cardboard around the bottle to make it dark. Worms do not like light and it will encourage them to burrow around the outside of the bottle so they can be observed.
  6. Place the wormery in a warm place. Remove the cardboard for observation periods and record findings. Check that the contents are damp and that there is food available for the worms.
  7. After one week, release the worms back into the garden.

Hints & tips

  • The layers disappear as the sand and soil mix together and channels appear where the worms have burrowed
  • The food from the top may be dragged downwards 
  • Do not feed the worms citrus fruits or onions
  • Use this activity as part of the Earth Matters class growing topic