The reasons why infants like to sleep in their arms mainly include satisfying the sense of security and easily entering deep sleep. 1. Satisfy the sense of security: infants like to sleep in their arms mainly because they can satisfy the sense of security by sleeping in their arms. Infants have just left the warm womb environment of the mother and need to gradually adapt to the external environment. Cuddling can make the baby have a sense of encirclement, and then let the baby produce enough sense of security. 2. Easy to enter a deep sleep: the sense of encirclement of the arm and the uterus is more similar to the wrapping environment, the baby is easy to enter a more relaxed state, and then easy to enter a deep sleep. This is also a common reason why babies like to sleep in their arms. There may be other reasons why babies like to sleep in their arms, but it is recommended that you try not to sleep in your arms for a long time, so as not to form a dependency.