Buddy always tried to get out and did manage to get out a couple times before I got him a harness and leash. Only thing is, when you take a cat out once, they will want to go out every day and bug you until you take them out.

When I started taking Bud out on his leash once a day he stopped hanging by the door so much. He got into a routine. Every night after dinner was time to walk the kitty. There way no way to forget this either...he would remind me.