We close ours after the girls have gone to bed. Did miss once because when I went out to check they weren't all in so I came back in planning on going again in half an hour or so...and fell asleep
Fortunately no harm came to them. Ours is secure however, it's wired all the way around...coop and run, and we don't have too many predators where we live...mostly hawks. Chances are slim that leaving the coop open overnight but...why take even a slim chance?
![Frown :( :(](/styles/byc-smilies/sad.png)