How do worms improve the soil? By eating it! In fact, a worm can eat its own weight in food each day. In loosely packed soil, a worm simply moves soil particles to the side as it tunnels in search of food (dead plants and animals, tiny seeds, eggs and larva). In compacted soils containing little food, worms eat their way through. Soil and food are passed through their bodies. As food passes through a worm's digestive system the unavailable nutrients (locked up in the food materials) are recycled into wastes called castings that are rich in the minerals (nitrogen, phosphorus and potassium) plants need.

To start your own worm farm (or vermicomposter), obtain a glass, plastic or cardboard container. If you are using a box, first line it with black plastic (a garbage bag works well). Slowly add 8-10 inches of soil to the container, moistening the soil every few inches using a water sprayer. Add 1-2 cups of vegetable scraps and mix it into the soil (the ideal worm to garbage ratio is 2:1; for example, add 1 ounce of food weekly for every 2 ounces of worms). If the container is made of clear glass or plastic, cover it with black paper or plastic. Covering the container with dark material will allow the light-sensitive worms to burrow close to the sides of the container. (You can periodically remove the covering to observe the worms and their tunnels.)

Make sure your worm bin has a lid with air holes. The lid will keep out rain and predators. Place the container in a cool, shady location (temperatures ranging from 55-77 degrees). Allow the soil to compost for a few days before adding worms.

To find your own worms, dig about 8 inches deep in loose, moist soil in the evening or just after a rain. Start with 20-25 worms. Redworms tend to work better in a vermicomposting situation as they can tolerate a wider range of temperatures. Redworms can be purchased at a bait shop (a one-pound container could hold 600-1,000 redworms).

The soil in the worm bin must be tended regularly so that it remains moist but not soggy. It should be stirred every few weeks to add air. If the soil conditions are favorable in your worm bin, new worms will hatch from eggs in a little over a month. You can remove some worms and compost on a monthly basis to add to your garden. To collect the finished compost, push the contents of the bin to one side and add new bedding and food scraps to the other side. Cover the new bedding with black material. When the worms migrate to the new bedding, scoop out the completed compost. In winter, the worm bin must be emptied or kept in a well-ventilated garage (that doesn't freeze) or basement.

WORMY FACTS

* Do not have eyes but have light-sensitive skin cells that detect light

* Breathe through their skin (exposure to dry conditions for longer than a few minutes can damage skin so that it can't absorb oxygen)

* Show taste preferences to different kinds of food

* Have four pairs of bristles on each segment called setae that anchor the worm and help it move

* Stick their front end out of the burrow at night (fewer predators and more moisture) to find food.

HOW TO DO IT

Recommended ages: 5 and up (younger children will need assistance)

Estimated time: 45 minute set-up; ongoing maintenance