Recently, my rats, have gone crazy. They used to be normal, chill rats. Now they fucking tear up the wall behind the cage, literally ripping off the plaster and wallpaper. They also destroyed their hammock which they've never chewed before. I don't understand what changed? I haven't really been spending much time with them, could this be the cause? They keep causing so much damage and my mom if going to get really mad if they become too bad. What should I do?