To help his cat go in and out, a man took one and a half hours to install a cat door. However when his cat wanted to go back inside, it simply stood up on its hind legs, turned the door handle, and pushed its way in, completely ignoring the cat door installed for its express use.

If the idea that a cat would completely invalid your efforts sounds familiar, then you’ve probably spent much of your life with your own cat. Still this shows that the cat is smart enough to use a real door and not a cat door, so you have to give the cat credit for that.