Squirmin' Worms

Pass out the All Extend Investigation Options handout. Explain to students that in this phase of the lesson, they are to conduct, in their groups, four experiments with the earthworms.

Ask students to make their observations and record their data for each experiment, either on the handout or in their notebooks (as suggested at the beginning of this lesson) using the handout as a template.

At the end of each experiment, ask each group to share their results with the class.

Investigation Part 2: How Do Earthworms React to Light?

Materials:

• Earthworm chamber (shoebox or plastic container with lid)

• Paper towels

• Black construction paper

• Scissors

• Tape

• Light source (flashlight or lamp)

• Earthworms (3 per group)

Procedure:

Guide students in setting up the earthworm chambers, similar to the one below if they are using a lamp:

If you are using a shoe box or containers without lids and flashlights, you can use the set-up below:

• After students have prepared the earthworm chamber, ask them to place two earthworms on the midline of the container (or where the dark side of the chamber meets the light side).

• Allow the earthworms to rest for 10 minutes and have students examine the chamber and document any movement or non-movement the earthworms make.

• Ask students to write down their observations and tally the worms' behavior.

Investigation Part 3: How Do Earthworms React to Different Temperatures?

Materials:

• Earthworm chamber (shoebox or plastic container with lid)

• Paper towels

• Access to tap water

• Access to hot water or a microwave to heat wet paper towels

• Access to a freezer or access to paper towels that have been wet and frozen. It only takes 5 minutes for them to freeze enough for the purpose of this activity

• Earthworms (3 per group)

Procedure:

Ask students to set up their earthworm chambers similar to the one below:

1. Paper Towel/Tap Water

• Ask students to moisten a paper towel using tap water at a cool temperature.

• Ask students to place their earthworms directly on the paper towel to observe and document their movement during a five-minute period.

• As in the picture above, the earthworms will probably stay on the towel.

• Ask students to remove the paper towel and the earthworms from the chamber, and prepare the next trial.

2. Paper towel/Frozen

• Ask students to moisten a paper towel and place it in the freezer, or pass out frozen paper towels that you have already prepared.

• Each paper towel should be flexible enough for a student to bend it up and down. You will know they are at the right temperature if they are bendable.

• Have students place their earthworms directly on the paper towel, observe, and document their movement during a five-minute period.

• The earthworms will probably stay on the paper towel, but movement will be more limited than when they were placed on the tap water paper towel. (The body temperature of the worms will drop when they are on the frozen paper towel, decreasing their movement)

• Ask students to remove the paper towel and the earthworms from the chamber.

3. Paper towel/Microwaved or using hot water

• Ask students to moisten a paper towel and place it in the microwave for no longer than one minute, or dip it in hot water, wringing out the excess moisture.

• The paper towel should be hot but not so hot the student cannot touch it or carry it to their earthworm chamber.

• Ask each group to place their earthworms directly on the hot paper towels and observe, documenting their movement during a one- to two-minute period.

• As in the pictures below, the earthworms will probably try to move off of the paper towel as quickly as possible. They may move under it or just off of it, seeking refuge from the heat.

• Ask students to remove the paper towel and the earthworms from the chamber.

Investigation Part 4: How Do Earthworms React to Vibrations?

Materials:

• Earthworm chamber (shoebox or plastic container with lid)

• Paper towels

• Tuning fork (if possible)

• Earthworms (2 per group)

Procedure:

Ask students to set up the chamber similar to the one below:

• Once students have the chamber set up, ask them to place earthworms on the right-hand side of the container.

• If using a tuning fork, have one student per group hit the tuning fork against a hard surface and lightly touch it to the bottom of the chamber directly underneath the worms.

• If not using a tuning fork, direct one student per group to lightly and quickly tap the bottom of the chamber.

• Tell students to keep tapping the chamber in the same spot, even if the worms move away from the source of the vibrations.

• Ask students to observe the earthworms' reaction for two minutes.

• The earthworms will probably move around the chamber trying to escape the vibrations. At the very least, they will move away from the source of the vibrations.

• Have students remove the worms and prepare for the next experiment.

Investigation Part 5: How Do Earthworms React to Odors?

Materials:

• Earthworm chamber (shoebox or plastic container with lid)

• Paper towels

• Vinegar

• Dropper of some sort to place drops of vinegar on a paper towel

• Earthworms (3 per group)

Procedure:

• Have each group pf students place several drops of vinegar on one paper towel, either on the left or the right side of the chamber.

• Once the chamber is set up, ask students to place the worms in the middle.

• Have students place a lid on the chamber and wait 10 minutes.

• After 10 minutes, as students to remove the lid and document any movement or non-movement the worms made.

Prepare a poster to share data:

After the experiments are conducted and the data gathered, have each group of students display their results from each experiment. To ensure students collect appropriate data, each poster should be based on the handout for each experiment. Each experiment needs its own data table, so each poster should have four data tables on it. The posters must have data tables like the ones in their handouts with specific numbers so that the worms' behavior can be quantified as a class. The posters can be made on oversized Post-its, bulletin board paper, or any medium large enough so the class can easily use it to collect data.

After all the posters are complete, have students do a Gallery Walk and gather class totals for each experiment. The data sheet for gathering class-wide data is attached, but again, it would be best if students used their notebooks. After the gallery walk, bring the class back together and have a discussion about their findings. Be sure to have groups who observed different data than everyone else explain how theirs was different, and why they think it may have been different.