Three-month-old babies love to eat hands may be due to conditioned reflex, hunger, lack of micronutrients and other reasons. 1. Conditioned reflex: three-month-old babies love to eat their hands, may be the sucking reflex, is a congenital conditioned reflex, is a normal phenomenon. But generally this phenomenon will gradually disappear after three months. 2. Hunger: it may also be insufficient feeding or to the time of the day should eat milk, the baby feels hungry, at this time will eat hands to express the signal of hunger. 3. Lack of micronutrients: If the body lacks iron, zinc and other micronutrients, the baby may appear to love eating hands. At the same time can also be accompanied by loss of appetite, hair yellow and other symptoms. Three-month-old babies love to eat their hands may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.