During our field studies at the wetland, I was somewhat surprised by students' fascination with the pill bug. Almost every student group spent considerable time observing this creature. It was by far the crowd favorite. I think partly because the pill bugs were so abundant. And, partly because it's just so fun to see pill bugs roll up into a little ball. Clearly, the students were interested in roly-polies. It was time to investigate!
Back in the classroom, we reflected some on the characteristics of living and non-living things. Then I brought up the pill bug. Why did we see so many pill bugs at the wetland? Are pill bugs specially adapted for wet environments? Or, can you find pill bugs anywhere? Most students agreed that pill bugs could be found anywhere. That is, they were not specially adapted to a wet environment. Then I asked, "How could we test that?"
We decided to set up mini habitat boxes for our pill bugs, varying one habitat component at a time. Our question was: What kind of habitat do pill bugs prefer? We set up three boxes in all, testing a wet vs. dry environment, a dark vs. light environment, and a warm vs. cold environment. We added 20 pill bugs to the center of each habitat box. Then we waited 15 minutes, and counted how many pill bugs were on each side of the box. The results are shown here.
We decided to set up mini habitat boxes for our pill bugs, varying one habitat component at a time. Our question was: What kind of habitat do pill bugs prefer? We set up three boxes in all, testing a wet vs. dry environment, a dark vs. light environment, and a warm vs. cold environment. We added 20 pill bugs to the center of each habitat box. Then we waited 15 minutes, and counted how many pill bugs were on each side of the box. The results are shown here.
Students predicted that pill bugs would prefer a dry, dark, warm environment. Our hypothesis was correct in part. The pill bugs clearly preferred a dark environment. But it turns out pill bugs also prefer wet, cold environments. We did not predict that! When we returned to class today, we recorded these surprising results in our science journals.
A student asked me today what I did with the pill bugs after our experiment. I told them that I put them back in their habitat outside. They were sad because they wanted to keep them as pets. Hmmm...What would we feed a pet pill bug? What do pill bugs like to eat? Doing science always leads to more questions! We will keep thinking about how pill bugs interact with the living and non-living things in their environment. (I wonder what role pill bugs play in our wetland ecosystem?)