Three and a half months of the baby does not eat milk may be related to the emergence of taste, oral diseases and indigestion and other reasons. 1. Oral disease: If a three and a half month old baby does not eat milk along with abnormal manifestations such as drooling, frequent opening of the mouth and crying, it may be due to lesions such as oral ulcers or herpes in the baby’s mouth. When drinking milk, touching the wound will trigger pain, so the baby does not eat milk. 2. Indigestion: indigestion of three and a half months of the baby because of the digestive tract to retain a large amount of milk, may lead to bloating, loss of appetite, no sense of hunger, so do not want to eat milk. 3. Physiological factors: the baby gradually grows up, attracted by external things, appear physiological anorexia, generally good spirits, no other discomfort. If the three and a half month old baby does not eat milk, it is necessary to go to the hospital in time to check the cause, so as not to delay the condition.