Hey
toland
I agree with
amylynn2374 and
Yorkshire coop in that it does not sound like normal broody behaviour.
Has she slept on the roost in the past?
If she has, I wonder if anything has changed which has caused her to feel more comfortable on the floor in a nest.
Maybe one of the other hens is picking on her or there is now not enough room for her on the roost.
Sometimes chickens are reluctant to roost if there are red fowl mite biting them during the night. Red fowl mite tend to hide in the cracks and crevices of the coop and roost and come out at night and feed on the chickens.
If she has never slept on the roost, it does sound like she has just got into a habit of sleeping on the nest.
As
Yorkshire coop suggested, I have had a nest box sleeper and blocking off the nest box in the afternoon has cured her of the habit.
Also, if she has never slept on the roost, I wonder if she is able to reach the roost, is it maybe too high for her? Some breeds, Silkies etc, are not good at getting onto a high roost.
Might be an idea to not leave eggs in the nest and ensure all have been collected in the afternoon.
Good luck with her
