A Bug's Life: Under A Rock!

Joan McKinnon
Lincoln Elementary School
Bemidji, MN
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Summary

In this classroom biology lab, students will investigate the role or purpose of decomposers. After collecting and observing a decomposer, the pill bug, the students will create habitats that they believe will sustain the bugs over time and will also continue to monitor and observe them throughout the school year.

Learning Goals

Students will gain a better understanding of food webs and the role of the decomposers in an ecosystem. Students' critical thinking skills will be enhanced as they create questions and find answers through observations of the Pill Bugs.

Context for Use

This activity is intended for an elementary classroom setting with approximately 25 students. While the initial activity will take three to four days, it is intended to be an activity where observations are regularly maintained throughout the year to monitor the activity of the Pill Bugs.
Materials Needed:
1. Clear plastic containers, such as 2 pound deli containers or clear pop bottles.
2. Leaves, soils, water, dark paper, etc. to create habitats.
3. Pill Bugs, Preferably, a few for each team of student pairs but students can work in bigger teams if necessary.
To obtain the Pill Bugs, teacher can:
a) order them
b) have the students collect them from under rocks
c) students or teacher or both can create pill bug "traps" (hollow out potatoes then connect them back together with toothpicks) leave them over a night or two in basements to catch pill bugs.

Description and Teaching Materials

I: Introduce this activity by reading the book,"Under One Rock - Bugs, Slugs and Other Ughs" by Anthony D. Fredericks, illustrated by Jennifer DiRubbio. Read up to the page where the boy looks under the rock then stop reading and have the students make predictions about what the boy will find under the rock and record the student predictions.
II: Take the students outside to a predetermined area where rocks are located, and have pairs of students do their own looking under rocks and record or draw what they actually find.
III. Return to the classroom, discuss the student observations and any questions that they have.
IV: Finish reading the story, discuss whether or not the students' findings matched with what the boy in the story found and resolve any questions that were answered by this point.
V. Discuss all of the questions still needing to be answered, hopefully, students will want to know what the bugs eat, why they live where they do, whether or not they prefer moisture and/or the dark, and a variety of other questions. Students should write their questions in their journals.
VI: At this point, the student pairs will need to think about their findings and what they still want to know. With this information in mind, the team needs to decide what they need to provide the pill bugs to sustain their life and also what to create as a variation in their second (or third) habitat to provide insight to questions that they have.
VII. The teams of student pairs should create two or three habitats with the clear plastic deli containers. The first habitat created is their control-such as just dry leaves, the other(s) contain variations to observe such as the leaves are dampened, or darkness is provided, etc. Once the habitats are created, they should be documented and labeled and then the pill bugs are placed into it.
VIII. Students should regularly monitor, observe, journal and maintain the life within their habitats.
IX. Discussion should occur periodically to provide time for students to share their findings and observations throughout the year.

Teaching Notes and Tips

Pill bugs feed on decaying plant material so that are great for the classroom as they will not bite. They are also plentiful in nature (and in our basements) so are also economical for classroom use as well.
I have not used pill bugs in my classroom before. I am hoping that by each student creating their own habitats, they will conduct better observations, which will hopefully provide keen insights into the role of decomposers.

Assessment

My assessment will be conducted through informal questioning of each individual student as they are monitoring and recording the observations of their habitats.

Standards

IV. Life Science: Flow of Matter and Energy
2.The student will use food webs to describe the relationships among producers, consumers,and decomposers in a MN ecosystem.

References and Resources