Earthworms are decomposers. They consume decaying matter and return the nutrients to the soil. Collect soil from outside and use half for this activity, and save half to use in the ROT AND NEW GROWTH activity. Students can help set up, then observe the earthworms for one or two weeks.
- A transparent container (glass aquarium or plastic fish bowl)
- Soil from outside
- Earthworms
- Non-meat food trash
- Water
- Dark cloth to cover container
- An outdoor place to conduct activity
Fill the container with soil just below the top.
Put Earthworms in the soil. Place food trash on top of the soil.
Add only enough water to keep soil damp, but not wet. Keep the container covered and in a cool place until time for students to make observations.
Students can predict what they think will happen to the food scraps and the soil and record their observations. (Things to look for: The food scraps will decay. Earthworms make tunnels through the soil and mix it up. The texture of the soil changes after passing through the earthworm body.)
Return earthworms to outdoor soil. Save the soil in the container for the ROT AND NEW GROWTH activity.
Ask students how they think earthworms change soil. (Their tunnels expose soil to air and let water seep down. The organic matter thy eat passes through their bodies to make richer soil.) What would the soil be like if there were no earthworms?
