[New Hampshire lover]

If the coop is really dark even when the pop-hole is open in the day will the hens go in and just sleep??

[ness]

I don't think so.
I have a large rabbit hutch as a hen house, i have covered the mesh with plywood.  This makes it very dark inside and none of mine have gone to sleep other than at night time.  
Hope this helps
Ness

[richyrich7]

No it will encourage them to go in to lay tho' they like somewhere dark and safe to lay.