Worm composting -- also called vermicomposting -- uses specialized worm species to break down organic waste. Composting with worms is a continuous process that can be done indoors or outdoors, and you don't have to turn the material because the worms do it for you. Typically, red wiggler worms are used in vermicomposting and are slightly different than a regular earthworm.
The body of an earthworm is divided into segments, and it is typically reddish-brown in color. Earthworms range in size from as small as 1/4 inch in length to 6 inches or longer. The largest earthworm ever recorded was found in South Africa and measured 22 feet long. Red wiggler worms are typically between 2 to 3 inches long and have a reddish-purple color and a yellow tip at the tail. Some species of red wiggler worms also have stripes.
The red wiggler worm -- also called red worm, brandling worm, manure worm and tiger worm -- is most commonly used for composting because it thrives in the warm conditions found in a compost bin. Red wigglers are adaptable, tolerating temperatures from 32 degrees Fahrenheit to 95 degrees Fahrenheit. They are also great breeders that feed on a range of organic waste and the microorganisms living in that material. Red wigglers aren't typically found in your backyard. Earthworms are ideal for outdoor gardens and are often found in your backyard and flower beds. Because they need moist soil to survive, they will burrow deep into the ground if the conditions are dry or cold.
Earthworms remove dead organic material from the surface of the soil and carry it underground. Earthworms will eat up to their body weight in food daily. Soil quality is improved through their castings -- feces -- which provides nutrients for plants. Red wigglers also improve the soil, but are more aggressive than earthworms. They will also eat up to their own weight in food daily, but red wigglers always remain near the surface of the soil where they feed on dead plant material. They speed up the composting process by eating a large quantity of dead organic material and leaving castings behind for living plants to feed on.
Because they reproduce more rapidly than earthworms and stay near the surface, red wigglers are more ideal for composting bins. Earthworms can kill themselves trying to burrow through the bottom of a worm bin because they are a burrowing worm, which means they prefer to stay well below the surface. In composting, this isn't ideal because the worms aren't gathering the surface material, and you may have to turn the compost to introduce them to new material.