Ozzy Osbourne suffered sleepless nights while his son JACK was performing daredevil stunts for TV show Adrenaline Junkie. The legendary rocker is famed for his wild onstage antics - which include biting the head off a bat - but he was so worried Jack would hurt himself he would lie awake night after night. The 20-year-old admits he added to his father's concerns by answering his phone while climbing mountains. Jack says, "Mum and KELLY told me that Dad was worried and not sleeping very well, but he knows that I can look after myself. I do have a habit of answering my phone when I'm half way up an mountain though, which scares people because they think I'm going to fall off."