It is normal for a newborn to have an invisible jumping fontanelle. The fontanel is a bone gap formed due to the lack of union between the cranial bones of the newborn at birth, and is mainly used to assess the growth and development of the newborn’s cranial bones and brain capacity. Under normal circumstances, most newborns cannot see the newborn fontanel jumping, but some of the newborns have thin subcutaneous fat, which makes it easy to feel the jumping. The fontanelles can be divided into anterior and posterior fontanelles. The posterior fontanelles are small or already closed at birth and close at the latest around 6 to 8 weeks. The anterior fontanel starts to get smaller at around 6 months of age and closes at the latest at 2 years of age. If it does not close for a long time or if there is any abnormality in the circumference of the head, it is recommended to go to the hospital for examination.