<P> Other animals, such as rabbits and rodents, practise coprophagia behaviours--eating specialised faeces in order to re-digest food, especially in the case of roughage . Capybara, rabbits, hamsters and other related species do not have a complex digestive system as do, for example, ruminants . Instead they extract more nutrition from grass by giving their food a second pass through the gut . Soft faecal pellets of partially digested food are excreted and generally consumed immediately . They also produce normal droppings, which are not eaten . </P> <P> Young elephants, pandas, koalas, and hippos eat the faeces of their mother, probably to obtain the bacteria required to properly digest vegetation . When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to get any nutritional value from many plant components . </P> <P> An earthworm's digestive system consists of a mouth, pharynx, esophagus, crop, gizzard, and intestine . The mouth is surrounded by strong lips, which act like a hand to grab pieces of dead grass, leaves, and weeds, with bits of soil to help chew . The lips break the food down into smaller pieces . In the pharynx, the food is lubricated by mucus secretions for easier passage . The esophagus adds calcium carbonate to neutralize the acids formed by food matter decay . Temporary storage occurs in the crop where food and calcium carbonate are mixed . The powerful muscles of the gizzard churn and mix the mass of food and dirt . When the churning is complete, the glands in the walls of the gizzard add enzymes to the thick paste, which helps chemically breakdown the organic matter . By peristalsis, the mixture is sent to the intestine where friendly bacteria continue chemical breakdown . This releases carbohydrates, protein, fat, and various vitamins and minerals for absorption into the body . </P> <P> In most vertebrates, digestion is a multistage process in the digestive system, starting from ingestion of raw materials, most often other organisms . Ingestion usually involves some type of mechanical and chemical processing . Digestion is separated into four steps: </P>

Where is the complete digestion of food occurs