Will not go into coop after first egg

[KBMonroe]

My 3 ISA Browns started laying on Christmas Eve. The temperature has dropped here in Louisiana to the teens for a low. All 3 are laying their eggs in the nesting box in the coop and since then I have to put them up at night. They will not go into coop at night by themselves. Is this a normal reaction?

 

[Welshies]

You can herd them in at night to get them in the habit.

 

[sourland]

No, it's not a normal reaction. Have you changed anything about the coop ? Have you checked the coop for a mite infestation ? Is a predator attempting to get into the coop at night ? There is a reason they have changed their behavior.

 

[KBMonroe]

I have not changed anything. No evidence of mites or that anything has tried to break into run or coop. Literally the only thing different is they have started laying their eggs in the coop. Maybe they will start back going into coop at night soon.