National Teachers Enhancement Network: Lesson Plan

Lesson Plan: Worms in a Bottle
Subject: Earth and Space / Earth Science / Soils
Classtime:
Total: 3 class periods (50-minute periods)

1-2 (research worms)
1 (construct worm bottles)
5 to 15-minute periods once or twice per week to allow monitoring, recording of data, feeding, and harvesting of worms pertinent to the activity.

*Note: Since it takes Redworms 60 to 90 days to mature sexually, this activity will need to be conducted over a period of a semester or the whole year.

Grade Level: K-12

Materials/Technology:

one or more computer(s) connected to the Internet (suggested)
one 2-liter plastic soft drink bottle for each student or group
one small tray or pie pan to set bottle in to drain.
various soils (from a local source: school grounds, home, etc.)
litter (for bedding) such as shredded newspaper, corrugated cardboard and/or leaves and grasses
1 dozen earthworms for each bottle (ordered or found locally)
nail and pliers, heat source (Bunsen burner, candle, propane torch)
dark construction paper or similar material (to cover the bottles)
fruit and vegetable table scraps for food
science journals/learning logs

Safety, Handling, Disposal:

Close supervision of students when burning holes in bottles with heated nails.
Wash hands before and after working with the worms and their environments.
Wash all surfaces after working.

Learner Outcomes:
Students should be able to:

Construct worm bottles.
Observe and record information about the life cycle of the earthworm.
Determine the effect earthworms have on the soil.
Investigate the contribution worms make to composting.

Problem/Purpose:
By participating in this activity students will gain a better understanding of the worm and its role in the recycling of organic materials into simpler forms.

Background/Inquiry:
Growing worms in a bottle is a viable on-going investigation/activity useful for any classroom. Worms can be used to help break down food scraps and other biodegradable products that might otherwise be discarded into landfills. The study of worms and their role in composting (as well as aerating the soil) reinforce biological and environmental themes such as food chains, relationships of living organisms, interaction with the environment, carbon and nitrogen cycles, and ecosystems.

Worm compost is made in a container filled with moistened bedding and redworms. Add food waste, and with assistance from microorganisms, the worms will convert bedding and food waste into compost. Worm composting can be done year-round (indoors or outdoors) in schools, offices, and homes. It is a natural method for recycling nutrients in food waste without odor. The resulting compost is a good soil conditioner for house plants, gardens and patio containers.

Before beginning this activity students could research and investigate the life cycle and feeding habits of the worm. Two good links to begin this study are:

www.mastercomposter.com: http://www.mastercomposter.com/

The Composting Council of Canada: http://www.compost.org/

*Note: A link is not totally necessary. Worm research can be done via school or community libraries. Or, if the teacher desires, no research need be conducted prior to the activity and an inquiry approach could be utilized. Students could conduct inquiry learning through the scientific process inherent in careful observation and recording of data gathered while maintaining their worm bottles.

During this project, students will be able to observe:

Worm eggs.
Worm growth and development.
Worm feeding habits, including foods the earthworms will or won´t eat.
Worm tunnels in soil.
Worm castings.
The way worms add humus to the soil.
The environmental effects of light, heat, water and vibrations on worms.

Vocabulary List: Here.

Hypothesis:
Have students make hypotheses about the worms or the project itself. This will vary according to grade level. For instance, the examples below might be applicable to grades 1-3.

Example: The worms breathe through their mouths. (OR) The worms will eat plastic.

Procedure:
Time frames will vary according to normal classroom variables. Procedural steps are sequential and should be arranged according to classroom teacher preference.

Classtime will consist of various activities to learn about worms (including access to information on various web sites over the Internet) and the construction/maintenance of student-made worm bottles. Fieldwork could consist of gathering soil and worms.

Grouping or non-grouping of students is deferred to the classroom teacher. A journal/learning log is recommended for student records. It will be best to set aside one consistent short period of time once or twice for the students to observe and record data pertinent to the worm bottles.

Prepare the bottle.

Cut off the top of the bottle. Leave enough of the top so it can be slipped over the remaining cylinder as a top cover. This should leave a cylinder about 8 inches high.
Use pliers to hold the nail, heat the nail, and to make several drain holes in the bottom of the bottle.
Make a cover out of black paper (or some other material) that can easily slip over the outside of the bottle. This cover should remain in place at all times to provide darkness in the bottle. Make it easy to slip on and off the bottle for adding food scraps and making observations.

repare the bed. Fill the bottle to within 1 inch of the top with either the soil or litter or a combination of both. *Note: The choice of bedding for the worms can be varied. Try different soils/bedding products and compare them with each other. The bedding should be kept moist but not waterlogged.

Add the worms. Worms may be purchased or collected from another compost bin, an aged manure site, or a soil site with a good population. The best worm for composting appears to be redworms (Eisenia foetida and Lumbricus rubellus).

Start out with one dozen worms per bottle and observe the population change over the time of the activity (see harvesting instructions (Procedure #6) for ways to count populations of worms).

Add the food. The fruit and vegetable scraps should be buried under the top of the soil or litter. Fruit and vegetable scraps could be brought from home or taken from the cafeteria in the school. Avoid meats.

*Note: A 2-liter bottle with 40-50 worms should be able to handle about one-half pound of scraps per week. Scraps should be added in smaller amounts 2 times per week to prevent buildup of foodstuffs that could become odorous. Also, the introduction of non-biodegradable materials (such as minimal amounts of plastic) may also interest the class and provide for discussions relating to recycling and waste control.

Observing and recording data.

Once (or twice) during the week, have students observe their worm bottles and make journal/learning log entries referencing observations.

*Suggestion: In each entry include:

Record keeping: amount of scraps added, amount of water added (if necessary), and descriptions of any activity observed in the bottles.
An observation of the bedding material (changes, non-changes).
An observation of the condition and presence (or non-presence) of food scraps.
A general record of the effects the worms have on the soil or litter (include drawings/diagrams as well as words).

*Note: These weekly observation times should also be used for maintenance on the bottles including addition of food scraps, extra litter, and/or the addition of small amounts of water to keep the bedding moist (only if necessary).

Once per month, have students harvest worms and do counts on how many worms are now in the bottle. List counts in journals. Return worms into the bottles.

Harvesting the worms and compost. At some point the population of worms will reach the maximum the container can carry or the litter will become completely composted. At this point both worms and compost must be harvested.

Several methods can be used to harvest:

Empty the compost and worms onto a newspaper and hang a light over them to drive the worms from the compost.
Devise a screen using a wire mesh or hardware fabric to separate the worms from the compost.
Record worm count and return at least 12 worms into the bottle if students wish to continue the experiment.
Record any material(s) that did not decompose.

*Note: The harvested worms can be used in other compost bins, bottles or released into a garden.

Results/Analysis:
Students should report on the worm life cycle and contribution to the recycling of organic material as observed through data collection.

This will vary according to the grade level. For instance, the examples below might be more applicable to the lower grades 1-3.

Reports could take a variety of forms.

Examples:

An individual written or oral summary of the results of the project including reference to the student´s original hypothesis.
Visual presentations of the various stages of the life cycle of the worm as observed or researched.
Tips and recommendations of how to best maintain worm bottles.

Conclusions:
Do the recorded observations of the worms support the hypothesis that was written? If a new hypothesis was to be written, how would it differ from the first?

Assessments: (if included)

Review science journals/learning logs. Grade according to criteria established by the teacher.

Integration: (if included)

Reflections:
Share your thoughts on this lesson with the NTEN team.

Please send an e-mail to Patti Harrison.

Extensions: (if included)

Addition of inorganic materials to the bottles could broaden discussions.

References/Resources: (if included)

Videos

Earthworms: Nature's Soil Builders Video 44-5569 1981 11 Min. STA P-I: The earthworm is one of nature's most industrious and beneficial animals. This video reveals the interesting activities of this secretive little creature, and shows how it improves the soil.

Order from: Stanton Films: 213-542-6573.

Composting Council of Canada: http://www.compost.org/
www.mastercomposter.com: http://www.mastercomposter.com/

Credits
Contributing Teacher: Harold Taylor
NTEN Course: The Dirty Dozen: 12 Lessons in Soil Science for Science Teachers
Instructor: Jim Bauder
Assistant Instructor: Paula B.
Developing Team:
T.L. Buck Buchanan, Cathy Hensel, Patti Harrison, John Usher, Don Wilson
HTML Programmers: Christy Cousineau, John Usher, Ching-Kwong Chia

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