1. Reasons why a four-month-old baby does not drink milk 1.1 Physiological reasons 1.2 Psychological reasons 1.3 Environmental reasons A four-month-old baby does not drink milk is a problem that many new mothers will encounter. This can be due to a variety of reasons including physical, psychological or environmental. Physiologically, your baby may be experiencing certain changes during growth and development, such as teething, increased food intake, etc. Psychologically, the baby may