What causes children to eat fingers?

In the clinic, parents often bring children of all ages to see a doctor, saying that children often eat hands? Is it a lack of trace elements? First tell parents that eating hands is not caused by trace element deficiency. The lips of infants under one year old are very sensitive. He likes to perceive objects and the world through the contact of lips. Therefore, infants eat hands without intervention. Preschool babies, that is, babies before the age of six, if they eat more because the children are not satisfied, they will appease themselves by eating their hands. Therefore, parents should not directly stop them, but they can divert their attention, provide enough security, accompany the baby more, and reduce criticism and tension.