Temperamental differences present in infants the moment of birth. Some babies are even tempered, alert, and predictable in terms of their sleeping and eating cycles. They adapt easily to change and enjoy new experiences. These children are described as having easy temperaments. Other children are irritable, difficult to distract, upset by new experiences, and unpredictable in terms of their sleeping and eating cycles. These children are often described as having difficult or feisty temperaments. Some adults, however, particularly enjoy children with “feisty” or “strong-willed” temperaments.