OUR RESIDENT CAT always seems to be on the "wrong side" of the door. Ella enjoys constant access to the garden and signals her desire by nudging a small doorbell suspended from the inside handle. We cooperate by opening the door but close it after her to keep the house warm and other critters (especially raccoons) outside. This saves the annoyance and expense of Ella's tugging on the drapes to get our attention. When we're not around, she's content to remain on either side of the door - until we come home.
The return passage can be a bit more complicated when the free-swinging pet door is unavailable (i.e., during the winter). Ella will sit outside and patiently stare through the glass, hoping for some help. If we don't respond, what's a cat to do? Ring the bell, of course.
But wait! Now the bell's on the wrong side of the door!