Effect of Environment on Pillbug Behavior
Courtney N. Aubain
AP Biology, Mr. Oak, Periods 7 and 8
Lehman High School
Abstract
We came to a conclusion that pillbugs would prefer moist environments to dry ones. We
conducted our experiment with ten pillbugs. Our setup was a choice chamber, we left one side
alone, while on the other we used a damp coffee filter. Then set the pillbugs lose into the center
of the choice chamber. Our prediction was right, the pillbugs ended up choosing the “Moist”
chamber.
INTRODUCTION
Pill bugs live in wet locations. They are found under damp objects or in organic garbage. If pill
bugs enter a building, they will often dry out and die.
(​http://www.pestworldforkids.org/pillbugs.html​) Because pillbugs breathe through gill-like
structures, they must live in moist places.
(http://outreach.mcb.harvard.edu/teachers/Summer05/ElizabethMick/PillbugBehavior.pdf) Their
diet consists mainly of leaf litter or pieces of fruits and vegetables. In this experiment we
attempted to see how environmental conditions affect animal behavior. We hoped to see how pill
bugs respond to different environments. We hypothesized that the pill bugs would go to the wet
side because they like moist environments. The independent variable is Time. The dependent
variable is number of pill bugs on wet side of the petri dish. The control is the the dry side of the
petri dish.
MATERIALS
1. Double Petri dishes (chamber with two sides and bridges)
2. 10 pill bugs
3. Water
4. Timer
PROCEDURE
1. Place a clean sheet of filter paper or paper towel disk into each side of the choice
chamber.
2. Dampen the filter paper on 1 side of the chamber. Make sure the paper absorbs all
excess water.
3. Use a plastic spoon to transfer 5 pill bugs to each side of the chamber.
4.
Put the lids on the chamber.
5. Count and record on the data table the number of pill bugs on each side of the
chamber every 30 seconds for 10 minutes. Continue to record data even if they all
move to 1 side or stop movin
Data
Time
WET SIDE
DRY SIDE
0:00
5
5
1:00
5
5
2:00
6
4
3:00
6
4
4:00
6
4
5:00
6
4
6:00
10
0
7:00
9
1
8:00
9
1
9:00
10
0
10:00
10
0
RESULTS
Chi-square for values on dry side
o
e
o-e
o-e^2
o-e^2/e
5 5
0
0
0
5 5
0
0
0
4 5
-1
1
.2
4 5
-1
1
.2
4 5
-1
1
.2
4 5
-1
1
.2
0 5
-5
25
5
1 5
-4
16
3.2
1 5
-4
16
3.2
0 5
-5
25
5
0 5
-5
25
5
Total
22.2
Chi-Square values of the number of pill bugs on the wet side.
o
e
o-e
o-e^2
o-e^2/e
5 5
0
0
0
5 5
0
0
0
6 5
1
1
.2
6 5
1
1
.2
6 5
1
1
.2
6 5
1
1
.2
10 5
5
25
5
9 5
4
16
3.2
9 5
4
16
3.2
10 5
5
25
5
10 5
5
25
5
Total 22.2
(Pennsylvania State University)
The chi-square calculated value is greater than chi-square. We reject the null hypothesis. The
difference between the observed and expected is statistically significant.
HANDOUT QUESTIONS
Based on your graph and the introductory material, explain pillbug behavior with respect
to humidity?
The pill bugs prefer damp/humid areas to dry ones. This is most likely due to the fact that they
have gills.
Explain how the pillbug response to humidity may be advantageous?
Pill bugs preference for humidity might allow them to burrow into the ground to seek humidity
and find food, or to prevent them from burning up.
Identify two more environmental factors that may affect pillbug behavior?
Two environmental factors that might affect pill bug behavior are the amount of vegetation and
temperature.
Design an experiment to test 1 of the environment to test 1 of the environmental factors
that may affect pill bug behavior?
An experiment may be effect of light on pillbugs.
The Independent Variable would be- Time
Dependent Variable would be-Number of pill bugs in light
Control would be- Darkness
CONCLUSION
Pill Bugs demonstrate an unmistakable inclination for damp soggy conditions over bone-dry
situations. This is most likely because of their having gills. We could determine the statistical
significance on grounds that the chi-square calculated value was 22.2 was more noteworthy than
the chi square critical value of 3.9. This can be beneficial in light of the fact that they don't need
to stress over discovering nourishment in the winter as their inclination for mugginess enables
them to tunnel into the ground to discover leaf litter. The amount of water on the paper may have
affected the results. The outside factors could have also contributed to the results, such as
lighting, vibration, or dampness of coffee filter. Also, as soon as we put all the pillbugs in the
chamber, we started the lab. If we had given five minutes or so for the pill bugs to be attributed
to the environment, the results may have changed. For the future, we may have had better results
if our choice chamber was better constructed, there were some parts that were lifted and
therefore made it harder for the pillbugs to climb over and then they just stood at whichever side
was more accessible. Overall, it was easy concludible that pill bugs have a much higher
preference for damp environments instead of dry ones.
REFERENCES
1. Bug Facts & Pest Information for Kids. (n.d.). Retrieved from
https://pestworldforkids.org/
2. Carolina Biological Supply Company. (2017). Pill Bug Behavior Choices. Retrieved
from
https://www.carolina.com/teacher-resources/Interactive/pill-bug-behavior-choices/tr4120
6.tr
3. Pennsylvania State University. (2018). The Chi-Square Table. Retrieved November 01,
2018, from https://onlinecourses.science.psu.edu/stat414/node/147/