Infants’ lower lip biting is usually caused by various factors such as hunger, eczema or psychological problems. 1. Hunger: If you fail to feed your baby in time, your baby will relieve his hunger by biting his lower lip and sending out a sucking motion. After you feed your baby in time, the phenomenon of biting the lower lip will gradually decrease and disappear. 2. Psychological problems: babies will also have tension, anxiety, stress, weaning or environmental changes, there will be the performance of biting the lower lip, can be appropriate to divert the attention of the child, including the lifting of the factors that cause tension, anxiety, may be able to alleviate the performance of the child biting the lower lip. 3. Eczema: food allergies, inhalants, external environmental stimuli, close clothing material is not appropriate, etc., may cause pediatric eczema, eczema around the mouth when the baby is uncomfortable, there will be biting the lower lip action. You can give the child a warm bath every day and apply moisturizer or emollient to the skin after the bath. Parents can take their infants to the hospital if they bite their lower lip so that intervention can be given as soon as possible.