After 3-4 months of age, the child will enter the milk aversion period for various reasons, which is not related to the mother mainly due to the following factors: 1. the demand for milk decreases, after 3 months the child’s growth and development gradually slows down and the demand for milk decreases a little. 2. the child will gradually grow teeth after 4 months and there will be discomfort during the teething period, causing resistance to milk. 3. the sense of playing gradually increases and is attracted to the outside world. 4. The bottle is unsuitable. As the child grows older, the bottle and pacifier need to be replaced regularly, and the unsuitable bottle and pacifier will also affect the child’s milk intake. As long as the child is in good spirits, normal urination and defecation, and no obvious discomfort, you can first observe the process.