September 23, 2013
The purpose of experiment one was to observe whether pill bugs preferred a dark environment to a light environment. The purpose of experiment two was to observe whether or not an even sample of twenty pill bugs took a preference to environments with different temperatures. Our goal in this experiment was to be able to conclude whether pill bugs preferred a warm or cool environment.
HA : The pill bugs will prefer the darker chamber as opposed to a light chamber.
HO : The pill bugs will show no preference between the light and dark chamber.
P: If the light in the chamber decreases, then the amount of bugs in that chamber will increase.
HA : The pill bugs will prefer the cooler environment over the warm environment.
HO : If ten pill bugs choose the warm environment, then the other ten will choose the cool environment.
P: If the temperature of the environment in the double-chambered petri dish increases, then the amount of pill bugs in that environment will decrease.
Double chambered petri dish
20 pill bugs filter paper
5 water droplets (per chamber)
1. Obtain 20 pill bugs
2. Place ten pill bugs in each chamber, making sure to keep them seperated until you begin timing the experiment.
3. Place a piece of filter paper in each chamber and add 5 drops of water to each piece.
4. After ten bugs have been placed in each chamber, cover one side with foil to create a dark environment on one side.
5. After covering on side of the petri dish immediately begin timing.
6. Every two minutes over a period of ten minutes, record how many bugs are in each chamber.
Double Chambered petri dish
20 pill bugs stopwatch filter paper
5 water droplets (per chamber)
1. Obtain 20 pill bugs.
2. Before placing the pill bugs in the double-chambered petri dish, heat one side with the heating pad on the highest level. Let the other chamber remain at room temperature.
3. Make sure that both sides of the petri dish remain uncovered, so that the lights in the lab are distributed equally and do not affect the experiment.
4. Add one piece of filter paper with 5 droplets of water to each chamber so that both sides have the same humidity.
5. Place an iPhone under chamber R to balance it out with chamber H as the heating pad has offset the balance of both sides.
6. After one side has been heated, allow ten pill bugs to enter the heated chamber (H) and ten pill bugs to enter the room temperature chamber (R). Immediately begin timing.
7. For every two minutes over a period of ten minutes, record the amount of pill bugs in chamber R versus the amount of pill bugs in chamber H.
8. At the end of ten minutes, remove the pill bugs and allow the petri dish to return to room temperature before cleaning up the materials.
Results Observations: We observed that the pill bugs generally stayed in the dark environment. We wondered whether or not the humidity or the cool temperature had any effect their choice of chamber. With further experimenting we may be able to prove that temperature of the chamber also has an effect on the pill bugs preference.
Figure 1: The effect of different light levels on pill bugs (Armadillidium