Students will perform a simple experiment on Sow bugs to determine if Sow bugs change their behavior when environmental conditions change. Since Sow bugs are crustaceans with gills, they need a damp environment of the exchange of oxygen and waste gases. In a damp environment, Sow bugs will spread out, usually beneath the damp paper towel. When the environment dries, the Sow bugs tend to group along the outside perimeter of the cup and pile up on one another. Researchers have indicated that the bugs pile up on each other to slow the rate of evaporation from their bodies. Piling up of Sow bugs is an example of animals forming groups to increase the likelihood of survival.
Observe how Sow bugs change their behavior when the level of dampness decreases.
PE: 3LS2-1 Construct an argument that some animals form groups that help members survive.
If you wish to dispose of the sow bugs, collect then in a re-sealable plastic bag, place them in the freezer for 3 days and then dispose of them in the classroom trash.
Precut the paper towels to fit the container bottom. Sow bugs may be kept in a terrarium for the school year.
Sow bugs will explore the entire bottom of the container while it is damp. After the container dries, they will group along the walls of the container and pile up, sometimes 3 to 4 bugs high.
Did the Sow bugs change locations when the cup was dry? Where did the Sow bugs go?
The Sow bugs moved to the outside of the container and piled up on top of each other.
How did the motions of the Sow bugs change in the dry cup?
They did not spend any time exploring the dry part of the container. The bugs stayed very close together.
Sow bugs must stay damp to breathe. How can the behavior of Sow bugs in the dry container be explained?
When the Sow bugs piled up, it helped the bugs retain the moisture in their bodies.
Use your observations to explain this statement. Some animals form groups that help members survive.
When the Sow bugs lost the moisture in their environment, they changed their behavior or adapted. To conserve moisture so they could breathe, the bugs piled up and stayed close to each other around the outside of the cup. Being in a group helped the Sow bugs stay moist so they could breathe and continue to survive.
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