In our continuing study of the animal kingdom we have been studying three phyla of worms: Nematoda, Platyhelminthes, and Annelida. The Annelids include the gardener's best friend - the earthworm. I picked these nightcrawlers up at the local convenience store which carries live bait. Some of the students were a little grossed out by working with live worms.
The students began their studies of the earthworm by elliciting nervous system responses. In a dissecting tray the students laid dry and wet paper towels and placed the worms in the middle, covered them with a piece of cardboard and waited five minutes. The worms of course prefer a wet environment, and therefore moved to the wet paper towel side of the tray. Then with the tray covered completely with wet towels the students covered half of the tray with the cardboard and shined a flashlight on the worms. Worms like it dark so they beat a hasty retreat to the side of the tray that was covered by the cardboard.
Lastly, we set up a couple of "wormeries." We layered soil, sand, dead leaves, and some vegetable scraps (potato and apple peelings) in a two liter plastic bottle. Then we introduced 3-4 worms to each bottle. You can see the worms tunneling through this bottle (They are the pinkish layer right above the sandy layer). In order to provide the worms with the environment they prefer we have dark paper sleeves around the bottles to block the bright sunlight, and we keep the soil moistened.
To wrap it all up we have studied earthworm anatomy and conducted dissections. Many students were anxious about the dissections, but admit when it was all over it wasn't so bad.
