I made a slide chart of my chicken broods' ages. I realized I enthusiastically over estimated some of their ages. Anywho, we put three nesting boxes in the coop and it's too soon.The oldest set that I have affectionately known as Brood No. 1 are only 17 weeks, duh. According to my reading they won't need nesting boxes until they are 20 weeks old. Oh well, I'm leavin' 'em in there. Brood No. 1 consists of four Ameraucana and four Buff Orpingtons, btw. I can use the time to think about curtains for their boxes.
I didn't bother with curtains in either coop that has next boxes. The nests are fairly dark and the hens seem to consider them secure -- almost all the eggs end up there anyway.
With the first group I opened the boxes and put in the golf balls somewhere around 4 months in hope of them getting the idea that this was a good place to put eggs.
After that first group, the adult hens have taught the pullets.