Babies do not drink milk may be a normal phenomenon, breast milk odor changes caused by, but also may be the baby suffers from mouth ulcers and other diseases caused by. 1. Normal phenomenon: babies usually do not drink milk voluntarily when they are full. After a period of time when the baby is hungry, the milk drinking will return to normal. 2. Breastmilk odor change: Breastfed babies, if the mother has eaten some special food, breastmilk odor will change, the baby is not familiar with will refuse to drink milk. 3. Mouth ulcers: If the body lacks vitamin B and other essential vitamins or dry weather and other causes of mouth ulcers in babies, drinking milk will lead to pain on the ulcerated surface, which will lead to the baby not drinking milk. In addition, other reasons such as thrush, gastrointestinal flu, bronchitis and other diseases can also have an impact on appetite, resulting in babies do not drink milk conditions, parents are advised to consult a doctor in a timely manner, follow the doctor’s advice to do the appropriate treatment.