Discover What Worms Need To Survive: Learn About Earthworms Through Observation Experiments

Test your scientific skills by observing how earthworms react to different factors in their environment. These activities won’t hurt the worms, and you get to see how an animal responds to changes in its habitat.

Collecting Earthworms

Look for earthworm castings in patches of bare soil, like in a garden or worn area in the lawn. Castings are little piles of soil – the leaves that passed through the earthworm’s body.

You will need to dig up some earthworms from your yard. This is easier to do after it rains because the ground is softer. After a hard rain, you may find many worms on sidewalks and driveways. If it is early in the day and the worms haven’t started to dry out, you can collect these worms. Put them in a box or a pail lined with damp (not soaking wet) paper towel.

You can also go to an area without many plants and stomp for earthworms. Look for worm castings. Then, stamp your feet on the ground a half dozen times. Watch for worms to come to the surface. No one is certain why worms do this. Some theories are that the worms interpret the sound of your feet as rain, and they come above ground, so they don’t drown. Another theory is that the worms translate the noise as a tunneling mole looking for dinner. Sometimes stomping on the ground to make earthworms appear works, other times it doesn’t.

Tools for Earthworm Observation

You will need:

• A few sheets of paper (printer paper or even cardboard from a cereal box)
• Paper towel
• Water (use a spray bottle set to a fine mist if you have one)
• An old, smooth china plate or a piece of glass
• A piece of black construction paper
• Tape
• A flashlight

Worm Experiments

Experiment #1: Do worms prefer a damp or dry environment? Set an earthworm in the middle of one sheet of paper. Lay a piece of damp paper towel over the dry paper approximately two or three inches from the worm. Watch how the worm responds. You can try this experiment with another worm, only set the damp paper four inches from the worm.

Experiment #2: Can earthworms move more easily over a smooth or textured surface? Set a worm in the middle of a smooth plate or on a piece of glass. Can the earthworm move quickly or slowly? Now, set the worm on the ground – either on a patch of soil or on a walkway that isn’t in the direct sun. On which surface can the earthworm move most easily?

Experiment #3: Do earthworms prefer a dark or light environment? Fold the sheet of black construction paper in half and then in half again. (It doesn’t matter whether you fold it the long way or the short way.) Refold the paper, so it forms a square tunnel and add a piece of tape to hold the shape.

Set the tunnel on a sheet of white paper. Spray or rub some water on both the white paper and on the inside of the black tunnel. Set the worm a couple of inches from the tunnel. Shine a flashlight on the worm’s body or set the paper outside in the sun. Watch the earthworm’s reaction.

After you have explored an earthworm’s habitat needs, return the worms to the location where you dug them up. Notice how this environment meets the worms’ requirements for survival that you discovered during the experiments.