This activity is designed to show the importance of worms for soil health. The use of different layers of soil and sand makes any mixing performed by worms more obvious. By putting food for the worms on top of the soil layers, students will be able to observe how nutrients are brought down into the soil.

Preparation

There are a few preparation steps for this activity. All of these can be done with children or by an adult independently. Including children is great for learning but will extend the length of the activity. Detailed step-by-step guidance is given below.

• Cutting the bottle - this can be done in advance as cutting into plastic bottles can be tricky for younger children, and supervising adults may wish to tape the sharp edges.
• Gathering the soil - it is best to use soil from the area that you are collecting the worms from.
• Gathering the worms - worms (and soil) are easier to find after wet weather, and in darker, shady places. Dig a hole in the soil or look under stones and pots.

Activity steps

1. Make your wormery by cutting the top quarter of the bottle off. If you are finding it difficult to cut the bottle, try pinching it to cut a small hole, and then cut round the bottle from there.
2. Cut a small slit in the top in the top section of the bottle (see diagram), so it can fit over the top of the bottom section.
3. If the cut edges of the bottle are sharp and could cause injury, then tape the edges.
4. Fill the bottom section of the bottle with layers of soil and sand, with each layer between 2cm and 3cm.
5. If the soil or sand is dry, spray each layer with water as it is put in.
6. Leave about 5cm between the top of the layers and the top of the bottom section of the bottle.
7. Add four worms to the top of the soil.
8. Add food for the worms on top. This can include (dead) leaves, grass, or vegetable peelings (potato and carrots are good, citrus peel or onions are not to be used).
9. Place the top on, and then cover the bottle with the black paper.
10. Put your wormery in a cool, dark place, such as a cupboard, and observe it daily, removing the black paper to see what the worms have been up to.
11. Release the worms back into the habitat you found them after a week.

Activity materials

• 1.5 – 2 litre clear plastic drink bottle
• Scissors
• Tape (optional)
• Soil
• Sand
• Worms
• Worm food such as leaves or vegetable peelings
• Black paper
• Water spray
• Digging tools / trowel / scoop for collecting soil and filling the bottle

Worms are amazing creatures. During this investigation, you will observe how they help soil and plants in three main ways. Their burrows help water move from the surface deeper into the soil. Worms eat dead leaves and grass as well as other vegetable matter and bring this food into the soil. Through mixing the different layers in the soil, worms help to bring nutrients into deep layers of the soil.

Here are some fun worm facts:

• There are over 7,000 named species of earthworm, with 26 of these found in the UK.

• Worms can eat their own bodyweight each day.

• Most of the earthworms you might find will be between a few centimetres and 15cm long.

• The longest earthworm found in the UK was 40cm and the longest earthworm ever found, an African giant earthworm was 6.7m (22 feet) long.

• Worms do not have ears or eyes but are sensitive to light and vibrations.

• Worms need to be moist to stay alive.

• An acre contains about 250,000 earthworms, with estimates also reaching an incredible 1.75 million.

• Earthworms are incredibly strong, being able to push more than 10 times their own weight. That is the equivalent of an adult human pushing a bison or yak.