A difficult child is often referred to as a BRAT, which is a four-letter word. A difficult child is a child who exhibits challenging behavior, such as tantrums, aggression, and disobedience. This type of behavior can be caused by a variety of factors, including developmental delays, trauma, or a lack of parental guidance. Difficult children often require extra attention and patience from parents and caregivers in order to help them learn how to manage their emotions and behaviors.