1. Reasons why babies sleep after feeding. It is very common for babies to sleep after feeding. This is because in the first few months after birth, babies’ brains and bodies are still developing and they need a lot of sleep to support them. Growth and development. Moreover, breast milk contains a substance called triple probiotics, which can promote the growth of beneficial flora in the baby\’s intestines, aid digestion and absorption, and also make the baby feel at ease and relaxed. 2. How to make your baby sleep well after feeding