(I) All children are naturally active. (II) If a child is inactive for a long period of time, he or she must be checked by a doctor to determine whether there is a problem. (III) However, many become overly active when, for instance, they are anticipating a birthday party. (IV) Still, such behaviour is markedly different from true hyperactivity. (V) Hyperactive children have trouble sleeping, they cannot sit still and they act impulsively.