The Behavior Response of Pill Bug (Rollie Pollie) in Moisture, Scent,and pH level

Abstract

This experiment was used to test animal behavior. We tested the response pill bugs had to different environments in three different experiments: moist v/ dry, unscented v/ scented, and acidic v/ neutral. By setting up environment chambers that portrayed those environments, we found that pill bugs prefer dry over wet, unscented over scented, and neutral over acidic.

Introduction

When one thinks of behavior, it is generally linked to action. Behavior is defined by action. Animal behavior, in short, is the action of the animal. The study of animal behavior is known as ethology, which has two starting points: ultimate and proximate questions. Ultimate questions address the "why" of the behavior. Why does this certain behavior happen? What does it accomplish? Examples of an ultimate question would be "Why do birds sing?"or "Do louder bird songs attract more mates?" Proximate questions address the "how"of the behavior. An example of a proximate question would be "How do birds know when to sing?" Some actions are fixed action patterns, meaning a certain action happens at an exact time over and over again. In animals, these actions have never been taught to them, but are instinctive. Mating calls are often fixed action patterns. For example, when peacocks mate, the male tries to impress the female by showing off his colorful feathers and doing a sort of dance. Animal behavior is not all instinctive. Imprinting is a time in a young animals life where the animal becomes attached to a parent and begins to copy certain characteristics from it. For example, geese, ducks, and some other animals can imprint on humans, or other animals outside of their own species. An ultimate cause could be that imprinting is essential to survival because of the goose's need for a parental figure. An proximate cause could be that it is an instinctive action to imprint on another living being. Kinesis is the nonspecific movement of an animal. The pill bug moved around randomly until it found a desired environment. Taxis is the direct movement in response to a stimulus. For example, birds migrating south would be a taxis movement because the cold climate is the stimulus to the migration. Classical conditions are where an animal associates something with an idea and its body responds to it. Ivan Pavlov's dogs are an example of classical conditions. Pavlov trained his dogs to come for food by ringing a bell. Whenever the dogs heard a bell ringing, they associated it with food and their mouths began to salivate. Operant conditions uses reinforcement to either increase or decrease a behavior. For example, a dog is given treats for obeying commands, while it is reprimanded for disobeying commands.

Hypothesis

Part 1: Moisture v/ No Moisture

If the pill bugs are given the option of two environments: one moist and one dry, it will choose the former because they are normally found in more damp places.

Part 2: Scent v/ No Scent

If the pill bugs are given the option of two environments: one scented with vinegar and one not scented, it will choose the latter because the pill bug's normal environment doesn't usually have any particular scent.

Part 3: Acidic v/ Neutral

If the pill bugs are given the option of two environments: one acidic and one neutral, then it will choose the latter because the pill bug's normal environment is at a neutral pH level.

Materials

Part 1

• 10 pill bugs
• 2 behavior chambers
• 2 pieces of filter paper
• paint brushes
• pipet 
• water
• timer

Part 2

• 10 pill bugs
• 2 behavior chambers
• 2 pieces of filter paper
• paint brushes
• pipets
• water
• vinegar
• timer

Part 3

• 10 pill bugs
• 2 behavior chambers
• 2 pieces of filter paper
• paint brushes
• pipets
• water
• HCl
• pH strips
• timer

Procedure

Part 1

To prepare the chambers we put two filter papers on either side and added water to one of them and left the other one dry. We then put 10 pill bugs in the middle of the two chambers with the paint brushes and covered the chamber with another chamber so the environment remained dark, like the pill bug's normal environment. We then started a timer and every thirty seconds we checked and counted how many pill bugs were on each side. We recorded seven minutes of data. 

Part 2

To prepare the chambers, we put two filter papers on either side and added water to one of them and vinegar to the other. We then put 10 pill bugs in the middle of the two chambers with the paint brushes and covered the chamber with another chamber so the environment remained dark, like the pill bug's normal habitat. We then started a timer and every thirty seconds we checked and counted the amount of pill bugs on each side. We recorded seven minutes of data. 

Part 3

To prepare the chamber, we put two filter papers on either side and added water to one of them and HCl to the other. We then put 10 pill bugs in the middle of the two chambers with the paint brushes and covered the chamber with another chamber so the environment remained dark, like the pill bug's normal habitat. We then started a timer and every thirty seconds, we checked and counted the amount of pill bugs on each side. We recorded seven minutes of data.

Results

Part 1

Most of the pill bugs stayed in the dry chamber, disproving the hypothesis that more would be in the wet chamber.

Time (min)	Wet	Dry
0	2	8
0.5	2	8
1	2	8
1.5	3	7
2	3	7
2.5	3	7
3	3	7
3.5	3	7
4	3	7
4.5	3	7
5	2	8
5.5	2	8
6	2	8
6.7	2	8
7	2	8

Part 2

The majority of the pill bugs moved to the non-scented chamber, proving our hypothesis that pill bugs preferred non-scented environments over scented environments.

Time (min)	Water	Vinegar
0	4	6
0.5	6	4
1	9	1
1.5	9	1
2	9	1
2.5	9	1
3	9	1
3.5	9	1
4	9	1
4.5	9	1
5	9	1
5.5	9	1
6	9	1
6.7	9	1
7	9	1

Part 3

The majority of the pill bugs moved to the neutral chamber as apposed to the acidic chamber, which proved the hypothesis that pill bugs prefer more neutral environments. 

Time (min)	Water	HCl
0	10	0
0.5	8	2
1	8	2
1.5	8	2
2	8	2
2.5	8	2
3	10	0
3.5	10	0
4	10	0
4.5	10	0
5	10	0
5.5	10	0
6	10	0
6.7	10	0
7	10	0

Conclusion

Other than the unexpected results from Part 1, Parts 2 and 3 were just as we hypothesized. In Part 1, we thought that the pill bugs would be more attracted to the moist climate rather than the damp climate, however it was the exact opposite. More pill bugs were attracted to the dry climate. In Parts 2 and 3, the pill bugs favored the damp climate rather than the scented and neutral climate. While vinegar and HCl were two extremes of scent and pH (independent variables), the pill bugs seemed to prefer more neutral environments. The amount of pill bugs in one chamber stayed constant for the most part, but that might have been due to human error. A lot of pill bugs crawled underneath the filter paper and some were placed on their backs so they didn't have enough time to orient themselves to their environments because they were too busy trying to get up onto their many feet. All in all, excluding Part 1, our results made sense and backed up our original thoughts on animal behavior.

Questions

1. What conclusions do you draw from your data? Explain physiological reasons for the behavior observed in this activity.

While their gills would suggest that pill bugs prefer damp climates, our experiment suggested that they preferred dry climates. That may have been due to errors in our experiment but it could also be an evolutionary development to more dry climates. 

2. How do isopods locate appropriate environments?

Isopods, like the pill bug, have antennae, which allows them to sense their surroundings. 

3. If you suddenly turn a rock over and found isopods under it, what would you expect them to be doing? If you watch the isopods for a few minutes, how would you expect to see their behavior change?

I would expect them to start moving due to the sudden exposure to sunlight, which is not part of its natural climate. I assume that once it finds a place close enough to its natural habitat then it will stop moving. 

4. Is the isopod’s response to moisture best classified as kinesis or taxis? Explain your response.

The isopod's reaction to moisture is classified as kinesis since they didn't exactly have a destination in mind when they moved. They were just looking for an environment that suited them best, which is more a kinesis response rather than a taxis response.

5. Identify the control(s), independent variable, and dependent variable in this experiment and explain why you have identified the factor you chose as each.

In Part One, the control was the dry chamber because nothing was altered. In Part Two and Three it was the moist chamber because there wasn't a scent or pH change. The Independent variable is the moisture in each chamber. The dependent variable was the amount of pill bugs in each chamber because it was the outcome of the situation that the pill bugs were put in. 

Citations

Behavioral Biology: Proximate and Ultimate Causes of Behavior. (n.d.). OpenStax CNX. Retrieved April 13, 2014, from http://cnx.org/content/m44879/latest/




    Cherry, K. (n.d.). Classical vs Operant Conditioning. About.com Psychology. Retrieved April 11, 2014, from http://psychology.about.com/od/behavioralpsychology/a/classical-vs-operant-conditioning.htm