Babies who are hungry are often characterized by crying, finger sucking and decreased frequency of urination and defecation. 1. Crying: Babies who are hungry will show signs of irritability, such as twisting and turning of the body, followed by loud crying and loud voices. 2. Sucking fingers: infants will make sucking movements when they are hungry, such as sucking fingers, and when the parents’ fingers touch the baby’s face, the baby will turn his face to make an eager search for action, which is a signal that the baby is hungry. 3. Decreased frequency of urination and defecation: If the baby’s frequency of urination and defecation becomes less and less in a day, it means that the baby may be hungry and not fed enough. 4. Other: If an older baby is hungry, he or she will show happy expressions and movements when seeing the mother come to the side or when seeing the bottle. In addition, when the baby ate the milk appeared eager swallowing action, big mouth sucking milk, indicating that the baby is very hungry. If there are other symptoms in addition to those mentioned above, you should go to the hospital in time to have the cause clarified and then give targeted treatment.