Survival: Sow Bug Behavior

A Carolina Essentials™ Investigation

Total Time: 30 minutes

Prep: 15 mins | Activity: 30 mins

Life Science


Grade 3


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.

Essential Question

Do animals change their behavior to help the group survive?

Investigation Objective

Observe how Sow bugs change their behavior when the level of dampness decreases.

Next Generation Science Standards* (NGSS)

PE: 3LS2-1 Construct an argument that some animals form groups that help members survive.

Science & Engineering Practices

Engage in Argument from Evidence

Disciplinary Core Ideas

LS2.D: Social Interactions and Group Behavior

Crosscutting Concepts

Cause and Effect

Safety & Disposal

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.

Student Procedures

  1. Put a clean paper towel disk into the cup.
  2. Use the dropper and water to dampen the paper towel. Make sure there are no puddles on the bottom of the cup.
  3. Use a plastic spoon to put 10 Sow bugs in the cup
  4. Watch the Sow bugs for 5 minutes. Describe the Sow bugs motions and locations in the cup.
  5. Draw a picture of the bug observations.
  6. Remove the damp paper towel from the cup. Make sure all the Sow bugs stay in the cup. Put the lid on the cup.
  7. Let the cup dry for about 5 minutes.
  8. Remove the lid. Watch the Sow bugs for 5-10 minutes. Describe the Sow bugs motions and locations in the cup.
  9. Draw a picture of the bugs observations.
  10. Clean-up: Return the Sow bugs to the place your teacher instructs. Throw the paper towel in the trash.

Teacher Preparation and Tips

  1. Put a clean paper towel disk into the cup.
  2. Check to ensure students just dampen paper towels and do not saturate them.
  3. You may wish to add the Sow bugs to the containers rather than have students transfer the bugs to the container.
  4. Students may use ovals or another symbol to represent the Sow bugs.
  5. Ask students to look carefully for the Sow bugs. Some may be underneath the damp paper towel. Students should count the bugs to make certain there are 10.
  6. Make sure the bottom of the container is dry.
  7. You may keep the Sow bugs in a terrarium for the duration of the school year

Data and Observations

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.

Analysis and Discussion

  1. 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.

  2. 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.

  3. 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.

  4. 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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*Next Generation Science Standards® is a registered trademark of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of, and do not endorse, these products.