I am the former "grandmom" of sasvermont's former bad boy, Gabe. I personally feel a big key to the successful overhaul in his personality has been the addition of cat mates as she said. I know my two boys have to roll and tumble around and let the fur fly every once in a while. I really do think they need this kind of activity to help burn up some of their pent-up kitty energy. Without it they might 'act out' on their humans. I am wondering if we could hear from some other "only kitty" moms and dads and see if this makes any sense. With Gabe he was friendly only to his immediate circle of two humans - everyone else had to watch out! Gabe also now spends his days breathing in that great Vermont fresh air, and lots of credit goes to Sallyanne for helping him all along the way and of course Graemer, a most charming host when he arrived who showed him the ropes.