Animal Behavior Lab (Pill Bugs)

Animal Behavior Lab Done with Pill Bugs (Rollie Pollies)

Abstract:

To order to gain a better understanding of animal behavior, we have conducted a lab in our biology class using pill bugs. To observe how pill bugs reacts to different environments, my partner and I did experiments involving pill bugs' preference to moisture, scent and terrain. In each experiment we used 10 pill bugs placed in a behavior chamber covered with filter paper. The behavior chamber is divided into two areas with different properties. For our first experiment (moisture), we drenched one filter paper with water and left the other dry, and after recording the pill bugs' movement for 7 minutes at 30 second intervals, we observed that the pill bugs prefered the wet environment. Our second experiment was conducted in the same way except instead of water we drenched the filter paper with honey. Our results did not show pill bug's reaction to honey/sugar. For our final experiment we put large beads simulating a rocky environment in one chamber while the other remained dry filter paper, we saw a large movement of pill bugs from the paper to the beads, thus demonstrating a preference for rocky terrain of pill bugs.

Background:

Animal behavior (ethology) is the way in which something acts or reacts by itself or to other beings. In ethology, questions regarding behavior is categorized into 2 types, proximate questions and ultimate questions. For example, when we study a bird singing, a proximate question would be "How did the bird tell when it's time to sing?" and a ultimate question would be "Why does the bird sing?" A fixed action pattern is a natural, innate behavior in a animal that does not change and not taught by others. For example, when a angry biology teacher smacks a disruptive student in the arm, the student instinctively and naturally cries out in pain and defiance (maybe not the latter in some countries); the reaction is innate since no one has explicitly taught the student to cry in pain when hit. Imprint is a type of behavior that is a combination of both innate and learned, it constitutes to an animal's response to a certain stimulus. In young geese for example, the ducklings will imprint on the behavior and characteristics of its surroundings, no matter the species. This can cause bizarre cases of young geese imprinting on humans or other non-predatory species. A proximate explanation could be that young geese are born incredibly clueless and need something to imitate, while a ultimate explanation could be that young geese lacks the intelligence to develop and learn basic behaviors on its own. In ethology, the response to a stimuli can also be categorized into kinesis and taxis. Kinesis is when animals respond randomly to a stimuli while taxis is specifically. For example, when pill bugs realize they are in a unsuitable environment, they will randomly move around until they find a better environment, for taxis, when the light were just turned on in a dark surrounding, insects and moths will immediately flock to it, it doesn't randomly find a place with light. Another distinction of animal reaction is classical and operant conditioning. Classical conditional is a involuntary/uncontrolled response to a external stimuli, such as a biology student screaming in pain as a teacher hits him. A operant response is a voluntary response in order to gain something, such as a student quickly wakes up when the teacher talks about the upcoming test, in order to achieve a passing grade.

Hypothesis:

Independent variable: Honey, water and beads

Dependent variable: Amount of pill bugs in each chamber

Moisture Lab:

If the pill bug prefers wet environments to dry environments, then pill bugs should undergo kinesis in the behavior chambers until they reach the other moist chamber, to which they should stay.

Honey Lab:

If the pill bug can detect scent, then pill bugs should undergo kinesis in the behavior chambers until they reach the honey covered chamber because bugs like sugar.

Terrain Lab:

If the pill bug hold preference over terrain, then pill bugs should undergo kinesis in the behavior chambers until they reach the bead covered chamber because they should be able to detect the terrain through sense of touch.

Materials:

10 pill bugs

1 behavior chamber
6 pieces of filter paper (for all 3 parts)
Brushes for moving bugs
Timer/clock
5 ml water
5 ml honey
30 small beads

Procedure:

Place 10 pill bugs into a behavior chamber covered with 2 pieces of filter paper, always leave one of the filter papers dry and untainted (control). The other piece of filter paper should be covered with water, honey or beads depending on the lab. Start the timer and cover the behavior chamber so light does not shine on the bugs. Every 30 seconds lift the cover and record down the amount of pill bugs in each side of  the chamber, continue on for 7 minutes with each lab.

Results:

Moisture lab:

Time (minutes)	# in Dry Chamber	# in moist chamber
0	2	8
0.5	2	8
1	2	8
1.5	2	8
2	1	9
2.5	1	9
3	0	10
3.5	0	10
4	0	10
4.5	0	10
5	0	10
5.5	0	10
6	0	10
6.5	0	10
7	0	10

Our results correlate with our hypothesis, showing that pill bugs do indeed prefer wet environments over dry environments.

Honey Lab

Time (minutes)	# in dry chamber	# in honey chamber
0	2	8
0.5	2	8
1	2	8
1.5	2	8
2	3	7
2.5	3	7
3	3	7
3.5	2	8
4	3	7
4.5	2	8
5	1	9
5.5	3	7
6	4	6
6.5	4	6
7	3	7

My partner and I's hypothesis wasn't entirely correct, we believe that the pill bugs had no reaction to the presence of sugar around him as the data shows the pill bugs movement as random and erratic.

Terrain Lab

Time (minutes)	# in dry chamber	# in bead chamber
0	0	10
0.5	1	9
1	3	7
1.5	5	5
2	6	4
2.5	5	5
3	7	3
3.5	6	4
4	7	3
4.5	9	1
5	10	0
5.5	9	1
6	10	0
6.5	8	2
7	9	1

Our lab results showed a great movement of pill bugs from the dry flat surface to the rocky bead covered chamber, this shows that pill bugs have a strong preference for uneven terrain as they quickly settled when they reached the beads,

Conclusion

Our results for our experiment showed that pill bugs preferred wet, uneven environments, and has no affinity to sugar or scent due to the amount of pill bugs staying dormant in their preferred environments, or undergoing kinesis in attempt to find a suitable environment. Possible error analysis in this experiment could be the amount of pill bugs present is not enough to provide reliable data, or the amount of time the pill bugs are left in their chambers isn't enough for them to demonstrate their behavior.

Works Cited

Emily Leck, "Chapter 51: Study Questions - Behavioral Ecology." Quizlet.com