I always give the nesting birds warning when I approach–I speak softly or whistle my favorite Snow White tune, even tap lightly before opening. When I open, like I did at this box, and she does not fly off the nest, I will NEVER force-flush her off just so I can count the eggs! Look at her expression–determined and brave girl! She is doing what comes naturally to her–even put her own life on the line (such as a predator attack which can end in tragedy) to protect her clutch. Who am I to tell she has to leave? I will close the box and leave her be to do her motherly care as she incubates her eggs. I will try again next box visit. Afternoons are good during incubation periods–she is more apt to leave the nest to take a break and find something to eat.