Originally Posted by EntropyControlSpe******t:
We lock our bedroom door. NOBODY is going in there (it is the only room "off limits" in our downstairs since the entire downstairs is a daycare ... 900+ sq. ft.). Nobody has ever attempted to go to our upstairs, but I would say, "Excuse me, but that is off limits." 
I would start opening the door saying, "We will see you tomorrow!" and staring while smiling.
I had a daycare mom go into our bedroom, chasing after her boy once!! That was the end of that!! I now shut all doors, to all bedrooms, etc. before pickup!!