LOL.
My cat does that with our bedroom door!
No fun in the middle of the night!
We have another cat that I shut out of the bedroom at night who has learned to jump up, hang onto the door knob (which is more of a handle or a latch than a knob) and he can open the door. This usually happens around 5 a.m. on the mornings that he decides to do it. Otherwise it happens whenever he wants in or out of a room. Fortunately he is not sucessful most of the time.