The Pill Bugs Response to Varying Light
By: Sarah Dorian
By: Sarah Dorian
Purpose:
The purpose of this experiment is discover the different ways in which pill bugs respond to varying light sources.
Experimental Hypothesis:The purpose of this experiment is discover the different ways in which pill bugs respond to varying light sources.
If pill bugs are found in light places, then they will be more likely to roll up into a ball becuase their natural habitat is in darkness, and therefore when they are out of their natural habitat they will feel the need to defend themselves, and thus roll into a ball.
Null Hypothesis:
If pill bugs are in an enviorment with bright light then they will not roll up into a ball because the variations of light have no affect on if they roll up.
Independent Variable:
The independent variable is the the varying degrees of brightness. There are three different levels of brightness, a dark, normal light, and very bright.
Dependent Variable:
The dependent variable is how many times the pill bugs roll up into a ball in each stage of brightness.
Control:
The control group for this experiment will be the pill bugs in the dark stage, because in their natural habitat pill bugs are normally live in dark areas, such as under rocks or plant beds. In addition, each container will all have moist surfaces so the pill bugs will feel comfortable in each scenario, and that the only variable changing their behavior is the lighting.
Constants:
The constants in this experiment is the moist surface on each jar, that will make each result similar to the pill bugs normal enviroment. The jars used for each group will all be the same as well, to eliminate any extra variables and make the experiement more accurate. The same temperature in each container will be the same. In addition there will be the same amount of roly polys in each container. The same amount of food and water in each container.
Repeated Trials:
In this experiement it was necessary to perform multiple trials in order to get more accurate results. Also many of the pill bugs reacted differently, therefore the more trials performed the more accurate the results.
Test Subjects:
The test subjects are pill bugs, or commonly known as roly polys. I chose these bugs as my test subject because there are many different ways in which to experiement on them, and they are relatively easy to find around Oak Park and River Forest.
Materials:
-flashlight
-4 pill bugs
-three peatree dishes
-normal lit room
-large lamp
-timer
Procedure:
1. Collect all materials, including nine pill bugs.
2. Place 3 pill bugs in each jar. In total their will be 9 pill bugs that will be experiemented on.
3. Next, once all of the pill bugs are in their proper location, have one jar go into an almost completely dark area, which should be similar to their natural habitat. Then place another jar by a normally light room. Then place the last jar in front of a very bright lamp.
4. Then, wait three minutes for each group, and count all of the times that the pill bugs roll up into a ball.
5. Repeat this experiment 5 times and record data.
Data:
Roll Up into a Ball
|
Dark
|
Normal Light
|
Bright Light
|
Trial 1
|
1
|
2
|
2
|
Trial 2
|
0
|
1
|
3
|
Trial 3
|
2
|
2
|
3
|
Trial 4
|
0
|
2
|
2
|
Trial 5**
|
Movement Around*
|
Dark
|
Normal Light
|
Bright Light
|
Trial 1
|
0
|
2
|
5
|
Trial 2
|
1
|
3
|
3
|
Trial 3
|
0
|
4
|
4
|
Trial 4
|
1
|
2
|
4
|
Trial 5**
|
*The scale used in the movement section of the lab was on a scale of (0 to 5). 0 being very slow, leisurely movement, and 5 being very aggresive and quick movement.
**A fifth trial was not able to be completed, due to the lack of movement of the pill bugs.
Graph:
The statistical tests used in this experiment was average and standard deviation. The averages for how many times the pill bugs rolled up into a ball are the following.
Dark: .75
Normal Light: 1.75
Bright Light: 2.5
The standard deviations of how many times the pill bugs rolled up into a ball were the following.
Dark: .957
Normal Light: .6922
Bright Light: .57735
The numbers received in the standard deviations were all below 1, which makes the data collected in this experiment more reliable, because this means that all of the numbers in the data are relatively close together. If the numbers collected are closer together, this means the risk of an extra variable is almost eliminated. The standard deviation test allowed the results collected to be confirmed as reliable.
Analysis:
During the many trials of experimenting on the pill bugs, many things came to the surface of the behavior of the pill bugs. For instance, while the pill bugs were in the brightest light (which is the most extreme setting away from their natural habitat), they seemed to almost go into shock and would either race around the dishes quickly in an aggressive matter, or immediately roll up into a ball as a defensive mechanism. While in the normal light, which was only slightly different from their normal environment, they seemed more comfortable but not completely calm. Than, in no light, the bugs seemed to be the closest to their natural environment and move at a slow constant rate, and were the most controlled and calm at this point in the experiment. Conclusion:
In this experiment the pill bugs reacted to the changing light as the following. In the brightest light, they would race around in shock, or immediately roll into a ball. In the normal light, the bugs behavior became slightly slowed down from their rapid movement in the bright light, and they tended to roll into a ball less. In the darkness, the bugs seemed the most confident, and would move at a regular slow pace that is seen when they are in their natural environment.
