This is a cross-post from our classroom website.

As part of our study of the flow of energy and matter through organisms and ecosystems we have been making periodic trips out to the creek behind the school. A couple weeks ago we constructed a food chain that might exist in the creek. The food chain featured a water strider.

To help us get a better sense of the lower parts of that food chain, we smeared microscope slides with peanut butter from the lunch room. With the peanut butter we hoped to attract small creatures in what microbiologists call a “biofilm.” It’s that layer of slime that you see on stuff in the creek.¹

Here’s a video from our classroom this week as we looked through a microscope that we projected on our TV in the classroom.

In the first clip, you can see what appears to be some sort of nematode (I think??) moving very quickly. To the left is what appears to be an amoeba? Other creatures (Rotifers? Euglena? Paramecium?) dart in and out of the frame. At one point, a large tubular creature darts into the frame and out again. The kids’ surprise is audible!

In the second clip is a cluster of creatures that appear to have flagella, which create a vortex that draws food near. The kids seemed fascinated by these. We watched for about 10 – 15 minutes.

One student, Mason, exclaimed: “It’s like the microscope slide is New York City!”, which is so true. The kids marveled at just how many creatures must be living in the creek if there are that many on just one microscope slide. Suddenly, the world got to be just a little bit bigger and more interesting.

PS. Thanks to the College biology department for their long-term loan of the microscope and camera and to Dr. Enos-Berlage for the idea to make biofilms in the first place. My special thanks go to Mr. Fitton who made many trips to meet me after school to set up the microscope for this venture. Without his help, this would not have been possible.