Children biting fingertips are common in the following cases: 1, psychological and behavioral abnormalities, mostly seen in the baby living in a divorced family, or abused in the family, the surrounding environment is poor, etc., can be caused by the baby biting fingertips and other abnormal behaviors. More parents to give care, while giving enough security, and the use of neglect therapy, do not pay too much attention to the behavior of biting fingers, otherwise it can only play a negative reinforcing effect. After caring and neglect therapy, there will be some improvement. 2, nutritional deficiency, when the baby exists trace elements, such as zinc, iron, copper and other trace element deficiency, easy to appear heterophagy, such as biting fingers, so you can take the baby to the hospital for trace element testing, according to the results of the symptomatic supplemental therapy.