Nine-month-old babies do not like to drink water, may drink too much milk, not enough exercise and other physiological reasons have to do with, there may be mouth ulcers and other physical discomfort, you can take general treatment, open throat sword and other medications. 1. Physiological factors: If the baby drinks too much milk, due to the amount of milk contains a lot of water, it will lead to not drinking water. In addition to this, insufficient exercise and insufficient sweating can also lead to not easy to be thirsty, which leads to the phenomenon of nine-month-old babies not drinking water. It is necessary to reduce the amount of milk in moderation, increase complementary foods, as well as increase exercise to improve the symptoms. 2. Mouth ulcers: When babies have mouth ulcers, they can appear not to drink milk, and when they drink water, they will have pain in swallowing and aggravate the discomfort. If there is fever, you can take ibuprofen antipyretic; open throat sword spray mouth, relieve oral discomfort symptoms, at the same time, you can add some zinc and vitamins in moderation, in order to repair the oral mucosa. There are other reasons for 9-month-old babies not drinking water, it is recommended to consult a doctor in time to identify the cause and treat the cause. The above medication is in accordance with the doctor’s instructions.