Letting her play in a card board box or anywhere dark ,cave like could lead to trouble .That being said i let my hen zons play around with those type of things because they enjoy it so much .Just keep it to a minimum. When my hens are hormonal i don't let them have those type of things either. Yes playing "house" might lead to the onset of harmones but not if you keep it to and hour or two every couple of weeks.If you don't stimulate your hormonal hen then you shoukdn;t have an issue with egg laying, but if you do there's several things you can do and that's another topic.Fat can stimulate zons because they breed during the dry season and high fat seeds and nuts are their normal diet at that time of the year,rainy season is more fresh fruits and other green plant matter. Amount of day light doesn't control zons breeding season much because they live in the tropics when the lengh of day changes very little, humidity on the other hand does have an effect because of the dry season is less humid, so when you run your heater in the winter you might be more likely to see harmonal behavior or egg laying.They're many factors envolved and good common sense is your best defense.