I akways tell my animals where I am going and it always breaks my heart to see them sitting there in the windows and looking at me and whining. If you have a new cat, it is always best to let them get introduced under the door when you are gone. That way they have time to get to know each other while you are gone. When you get home. open the door and let them play with each other while you watch. That.s how I did it and it worked well!!