Why do babies cry?

Babies cry in order to tell us things about their needs, as it is their only form of communication. The most common reasons a baby may cry are that they are hungry, have a dirty diaper, or are tired. Babies may also cry if they are hot, cold, or uncomfortable (gas pains, itchy clothes, rash). Babies do not cry to manipulate their parents; they simply are not capable of such advanced thinking and behavior.