Most of my students come from low-income families and live in apartment buildings. They are the children of immigrants — and often immigrants themselves — from Mexico and Central America. Although many of them have spent scattered time in rural farming communities, and their parents and grandparents have perhaps even farmed, I find that they usually have little experience with gardening, composting, or observing insects and invertebrates in the soil. Migrant children have sometimes worked in the fields of California and Oregon, but haven't often grown their own gardens.
I find that the worms in our classroom model healthy eating habits, which is important because my students eat a lot of cheap fast-food meals. Worms thrive on fresh fruits and vegetables. I teach the students that we must avoid putting sugary, salty, and fatty foods in the worm bin because they are not particularly healthy for the worms.
Redworms work quickly, and over the course of the first few weeks of school they eat the newspaper bedding and food scraps we provide and convert them to a dark, nutrient-rich, and odorless compost (this is called "vermicompost," or "worm castings"). The children are amazed when the first worm cocoons appear — tiny but visible lemon-colored globes, half the size of a grain of rice. With patience, we begin to examine baby worms hatching from the egg cases.
When we add food to the worm bin I bring up the concept of recycling. We begin the conversation, which will last all year, on what recycling means both for people and in the natural world. Cycles, in general, are an important curricular theme in 4th grade, and we look critically and in-depth at the process of recycling commodities. We examine the water cycle and life cycles of familiar animals and plants, including humans. There are many connections to our worm bin and endless opportunities for comparing and contrasting cycles.
At the beginning of the year many students are reluctant to touch the worms or even look closely at them, but by June the children have come to respect, care for, and sometimes even love our classroom worms. I find that the worms provide an ideal opportunity for teaching about animal stereotypes. Like snakes, spiders, or bats, worms have a negative image. At first, many children refer to the worms as "gross," "ugly," "disgusting," and "slimy." But after they learn about the hard work worms do in the natural environment, they come to appreciate them.