My neutered male cat is an extremely loud howler. He howls only when he's bored or wants outside. I recently caught him being a predator and have decided to not allow him outside any more. I know the howling will be unbearable, but I'm not going to give in. I would like to know, however, if anyone has any ideas as to how to control the howling while he's in the house. I've thought about the non-barking dog collars, but am unsure if they would work for a cat. Any thoughts or ideas will be greatly appreciated.