We have a butler door between the kitchen and dining room (door swings both ways). The kitchen has linoleum flooring,the dining room has carpet.I want him to be able to go back and forth. Right now he does a low volume whine when he can't get back through. I have taught Teddy to go kitchen to dining room(Does that easily) but he can't seem to get dining room to kitchen. Teddy has seen the cats do it. Today, I got down on all fours and did it with my head.(nothing) Put dabs of peanut butter on floor in kitchen, he ate what he could reach with his tongue under the door and nothing more. One of my wife's cats came through the door and ate the rest. I am running out of ideas does anyone have any suggestions?