Okay. I know WHAT a pop door is, I just don't know the why, when, where, and how's. First off, do I really need a pop door or can I just open the entry door a leave it open for them to get in and out. I have read that the pop door offers the chickens access to the coop in the event of an attck while keeping predators out of the coop and that does make a little since in theory, anyway. If I do make one, how big should it be? My coop is on the ground, so how high up should it be? And lastly, what is the best time to open in the a.m., should it stay open all day, when to close in the evening? So many questions for such a little door. My chicks are due in next Friday. Starting on my coop today.