The baby has the following reasons: 1, because the newborn baby’s nervous system development is not perfect, the phenomenon of jumping is normal, as the baby gets older, the jumping situation will disappear. 2, the child in the sleep of external influences caused by the baby jumping phenomenon, such as the family suddenly loud talking or closing the door sound will make the baby jumping situation. The baby can also be scared to jump in case of calcium deficiency, so you can take the baby for a trace element check to determine the baby’s calcium deficiency and then give the baby some milk calcium, and also supplement some cod liver oil to promote the baby’s absorption of calcium.