I was wondering about this. I have a broody hen who seems always sitting on the nest. Eggs or no eggs she just sits and does not lay. This has gone on for many weeks and most of last winter. I used this to introduce day old chicks under her this spring and she took to them well, took care of the chicks as they grew. Went back to being a hen again, laid a few eggs then immediately went broody again when her adopted children got big enough to be on their own. Just now though my adolecent rooster is starting to crow and is showing interest in his sisters. None of my girls are known brooders so I think I'll leave her be for now and slip a few, hopefully fertilized eggs under her in a few weeks.
Good information to know.
