When eating, drinking, defecation, and urination become irregular from 30 days old, it may be necessary to use digestive aids in moderation, such as probiotics, intestinal health products, and lactic acid bacteria tablets, and to apply a belly button patch. Babies have initially formed their own sleep, feeding, and defecation routines and habits. Some babies can already sleep for 4 to 6 hours at night, but there are significant differences between babies. Some babies still need to be fed 2 to 3 times at night by their mothers. Especially for breastfed babies, the feeding interval is shorter because breast milk is easier to digest. Each child has different habits; as long as the child is developing well, there is generally no problem.