Hi everyone! I'm brand new to keeping backyard chickens. Have started with only two young chooks (just off POL) and a pre fabricated coop designed for 4 chooks. I have done quite a lot of research but can't find WHY the coop has an internal door, with an external handle to open and close, between the 'run' area and the roosting box? The nesting box sits out from the side of the coop for easy egg collection. Should I be closing my girls in the roosting box at night for warmth and security or is the door for cleaning convenience? Look forward to hearing from you.