The benefits of vermicomposting with worms
In addition to increased nutrient levels, worm castings contain millions of microbes which help break down nutrients already present in the soil into plant available forms. As the worms deposit their castings, their mucous is a beneficial component absent from compost produced by hot or cold composting. The mucous component slows the release of nutrients preventing them from washing away with the first watering. Worm compost is usually too rich for use alone as a seed starter. It is useful as a top dressing and as an addition to potting mixes at a rate of one part castings to 4 parts mix.Your plants will love it.
Using vermicomposting bins
Unlike compost, which can work its magic in a pile in your backyard, vermicompost requires a bit more structure to work, usually in the form of a bin. Bins can be made out just about anything, but they require drainage and air flow to be built in, so things like styrofoam (very insulating, and may release toxins into the worms' environment) and metal (too conductive of heat and cold) are generally less desirable, and plastic requires more drainage than wood be it can't absorb moisture. The design of a bin usually depends on where you want to store the bin (in your kitchen, basement, backyard, etc.) and how they wish to feed the worms.
Most small bins can be grouped into three different groups; keep reading to learn more about the three categories of vermicomposting bins.