Redworms
(Eisenia foetida)

Redworms (bottom), compared to earthworms (top)

Worms contribute substantially to the process of composting.  You can find many worms crawling under or through an outdoor compost pile. As students create their own version of compost in the Soils unit (Lessons 2 through 13), they notice that worms break up the soil in the compost bags, making it lighter and fluffier.

Earthworms would be familiar animals for this activity, but they usually prefer climates cooler than room temperature. This is one reason they burrow underground. Redworms are a much better choice because, though smaller than earthworms, their general behavior is quite similar, and they thrive at room temperature.

Caring for redworms
Before the worms arrive, prepare a big dishpan or some other deep-sided pan or tray. Make bedding by spreading 8 to 13 cm  (3to 5 in) of shredded newspaper in the pan or tray. Dampen the newspaper with aged water—water that has sat out overnight to allow the chlorine to escape. 

Worms breathe through their skin, and if it dries out, they cannot breathe and die. So their skin must be kept moist at all times.  On the other hand, if there is too much water, worms cannot get enough air. Be sure to add water a little at a time until the newspaper bedding is moist but not soaked. If you happen to pour too much, add more shredded newspaper.

When the worms arrive, put them and the soil from their shipping container on the newspaper bedding. If they were shipped without soil, obtain some soil on your own—preferably garden soil—and spread a layer at least 3 cm (1 in) thick over the newspaper.

Redworms like to eat cornmeal or oatmeal. Give them a few tablespoons of food several times a week. Or they may like a piece of dry bread. Put their food on top of the bedding or bury it under the soil layer, but do not to push it all the way down into the bedding. If you overfeed redworms, the excess food may mold. If mold develops, simply scrape it off with a spoon.

There are several different materials you can use to cover the container, among them a damp towel, a damp piece of burlap or dark cloth, a large piece of black paper, or a piece of black plastic trash bag. If you choose a towel, burlap, or cloth, sprinkle it with water so it stays slightly damp but not dripping wet. If you obtain burlap from a feed dealer or mill, wash it well—it might contain traces of substances that could harm the worms. You might also place a sheet of dry cardboard over the burlap to keep out light. This permits the worms to crawl around in a darkened area not just at night but also during the day.

If you use a plastic trash bag, cut a rectangular piece and lay it over the pan or tray. Leave about a half-inch space around the edges to allow air to circulate freely below the plastic. If the worms try to crawl out, put the pan or tray in a lighted area. The worms stay under the black plastic to avoid the light.

Advisory on releasing redworms
The NSRC advises against the release of any organism used in the STC program. In some documented cases, environmental problems have resulted from the introduction of nonindigenous organisms. It is also illegal in many states to release organisms, even indigenous species, without a permit. The intention of these laws is protection of native wildlife and the environment.

The redworms used in this unit are commonly found throughout North America. Nevertheless, releasing them might encourage your students to release other organisms that could cause harm to native wildlife and local ecosystems. If you have any questions about releasing organisms in your area, contact your state or local environmental conservation agency.

Once you finish this unit, there are several things you can do with the redworms: