RALEIGH, N.C. -- Even as a toddler, Bradley Chubb had a motor. He'd sit down in front of the TV to watch cartoons, and a few minutes later he'd be crawling around the couch, bounding from one end to the other. He'd pick on his older brother -- a slap or a bite -- just to get his attention, then rumble back into the arms of his mother, Stacey, knowing he'd get off easy because he was the baby. To get him to nap, Stacey would lie down next to him, and wrap her arms around him like a straitjacket, tethering him to her chest.