BASIC ANATOMY AND LIVING REQUIREMENTS Knowing a few basics about worms and how they make a compost work will ensure you run a successful system that will keep you recycling at top efficiency indefinitely. Like any creature, worms need certain living conditions to keep them healthy, and, to understand and respect these requirements, a basic understanding of their anatomy and habits is essential. Worms are cold-blooded. This means they rely on environmental sources for body heat. There are thousands of different species world-wide, each with a different function to perform. They are loosely divided into two groups; earth workers and composters. Earth workers work at depths in the soil. They generally move and create burrows in a horizontal fashion but may come to the surface to gather food, hence distributing surface nutrients to various depths. Often quite large, their burrows channel water and air well below the topsoil.  While earth workers have an important role in the soil, they are not suitable in your compost. What you need are compost worms. These worms thrive in a rich environment and usually live near the surface creating burrows vertically between the surface litter and the safety zone of the soil under. The conditions you need in your compost are simply the appropriate safety zone, breeding conditions, moisture and predator protection for worms that will thrive on the varied diet of domestic waste. Living conditions At the bottom you will need to provide a generous 'safety zone' known as bedding. It will need to be deep enough to keep cool in Summer and not freeze in Winter for this is where the worms will retreat from the heat and rancidity of the rotting waste. It is where they will live while they are not eating. Castings deposited in the bedding will gradually build up from the bottom and create for the worms nature's own perfect bedding, being pH neutral, moisture retentive and comfortable. If the bedding isn't deep enough, the worms will retreat beneath the system into the soil under and you may lose them. Between the heat produced by anaerobic activity in the fresh waste and the coolness of the bedding will be a range of temperatures. It is within this range that the worms will find for themselves the perfect temperatures to mate and deposit their capsules which is generally between 16º and 25º C. Capsules will only hatch when conditions are right for the hatchling, i.e. There is moisture, comfortable pH, the right temperature and minimum disturbance. Given these conditions, which is usually found just under the fresh food, they will hatch in as little as two weeks while, in unfavorable conditions, they may take months, even years to hatch. This is why, after a drought breaks, worms seem to miraculously appear in ground that has been barren for years. Worms breathe through their skin, extracting oxygen from moisture in the soil and humidity in their burrows. A constant supply of fresh water will keep your worms healthy but enough drainage should be provided so water doesn't build up in the system or go stagnant as this will drown or poison the worms. Light also kills worms. Two or more hour's exposure is fatal. They will only come to the surface in daylight hours if they can hide under something. To encourage top-feeding in the compost, an old carpet will provide this cover for the worms and will also protect them from predators and minimize evaporation. Soil disturbance of any kind is detrimental to worms. 'Turning' a worm compost system will kill many thousands of baby worms, destroy the burrows and interrupt mating, slowing the composting rate dramatically. Remember that worms do all the work themselves, very efficiently, and turning the compost will not do them any favors. Fresh air is another major requirement. An air-tight lid will suffocate and/or overheat the worm system but in adverse weather conditions such as snow or heat-wave, protection which will allow air-flow is essential. In areas where the weather can be extreme, a large system is recommended as volume will provide the necessary climate control without requiring other measures to provide insulation. Worms prefer a pH around neutral but will survive quite well in acid or alkaline conditions. Once a compost system is established, the pH will correct itself naturally due to worm activity. Small white worms may appear. These are also earthworms which thrive in acidic conditions. Their presence will help neutralize the pH for other worms. Anatomy Worms are basically a very efficient digestive tube. Food (your waste) goes in one end and comes out the other as plant food (castings).  They have no eyes, ears or nose but a rather large, toothless mouth which inverts itself over a piece of food, then retracts to push the food directly into the digestive system. The food is processed by a secretion of calcium carbonate, millions of bacteria and other micro-organisms and also ground by grit from soil the worm ingests eventuating as nutrient and life-rich castings excreted from the anus. In an average adult worm, digestion takes about twenty-four hours. Ideally, food needs to be partially pre-composted for worms to eat which is achieved naturally in a worm compost system by a combination of aerobic and anaerobic bacteria and other biota. A worm's body is segmented. Surrounding a long muscle along the length of the digestive tube, each segment is a circular tube of muscle filled with water. This water can be pushed from one segment to another creating hydraulic motion. The water will be pushed to the back end of the worm (posterior) while the front (anterior) stretches forward. The front will then fill with water while the back retracts to catch up and so on. A worm can be short and fat one moment and long and thin the next. Similarly, when moisture is plentiful, the worm will absorb more and be larger than when conditions dry out. Spaced around each of the segments are setae. These are short bristly hairs with several functions. They are extremely sensitive to light and movement, warning the worm that it has surfaced or is in danger and they are also used for grip. When navigating a vertical burrow, the setae are used to grip the walls so the worm doesn't fall and they also help the worm to move along the ground. When a worm feeds on the surface, its anterior will be firmly gripping the burrow for a quick retreat if necessary. The segments are covered by skin and interrupted only by the clitellum (ring) which is always closest to the mouth end of the worm. A developed clitellum denotes sexual maturity, which in compost worms, will be at about two to three months. Worms are hermaphrodites, i.e. They are both male and female in one. They can self-fertilize but they usually mate in pairs.  During mating, two worms come together and overlap from the front to the clitellum. A thick gel is secreted around both worms and sperm is ejected under the gel to be stored in the sperm duct of each worm which each then goes its separate way. Immediately, a mucous ring forms over the clitellum which the worm begins to wriggle backwards out of and in doing so, ovum is collected from the ovary ducts and sperm from the sperm ducts thus resulting in fertilization within the ring. The ring then closes into a capsule as it slips off over the head of the worm. Each capsule will contain multiple babies and many capsules can be produced from the one mating. Because they need the right temperature for mating, breeding can drop off during extreme weather conditions but in a large system this is less of a problem. Adding extra food during winter will provide more warmth for worms and less food in summer will keep the system cooler. Worms may often be seen mating under the carpet covering a compost system. This is because the heat of the sun has provided the right temperature. Worms have an in-built ability to sustain the optimum population according to the available food and space. While conditions are right, they will breed at full potential until the desired food and space ratio is reached.  This is an excellent scenario in a compost situation as the more food you add, the more they populate.  A worm's circulatory system is controlled by several simple hearts pumping blood to a ventral vessel, a dorsal vessel and capillaries. They have a very sensitive nervous system of which the setae are major sensors and a tiny, insignificant brain. Although their anatomy is very simple, worms are one of the strongest animals on Earth for their size and have been around for 600 million years!