Lactating women have active mammary glands that secrete milk to feed their children over a period of time. Lactation usually occurs after pregnancy and could last as long as four or five years, depending on how long women choose to breastfeed their children. The milk comes out through the nipples, and the children suckle on the nipples to make the milk flow. Prolactin and oxytocin, the hormones responsible for milk production and secretion, make lactation possible in women. Lactating women have to maintain a clean lifestyle free of alcohol and tobacco and practice healthy eating habits because bad habits could hinder milk production. The milk produced provides nutrients for babies and has a very high nutritional value. It not only feeds children but also hydrates them.