I don't have a kitty door, but my friend was just telilng me this story. She always had a doggy door for her dog, Cinder. Her cat, Mojo, just detested using a doggy door, so my friend always left the sliding glass door propped open. Well, once Cinder passed away, they decided to heck with Mojo, he was going to learn how to use that doggy door. Well...Mojo refused. They tried everything, and he would not use it. Well, finally, they caught him using it. So, they started paying closer attention...Mojo had been using it all along, but only in private. She said it was like he was thinking "I'll be damned if I get seen coming through a doggy door." She said to this day, if they are near the doggy door (renamed kitty door for Mojo's sake), Mojo will not use it.