Unless they’re broody, chickens don’t give a hoot in hell if we take any eggs, unfertilized or fertile. Sorry if this doesn’t fit your mother hen as a loving devoted mother cherished idea but, fact is?
Hens are totally indifferent to their eggs except and unless nature has kicked in and told them to brood, and when that instinct kicks in?
They’ll brood anything in a nest, chicken egg, duck egg, stray kitten, rock or snake(!).
They only know it’s round or about the right size and they “HAVE” to sit there. They actually don’t have a serious clue it’s their potential offspring when they lay eggs. To them, it’s just instinct that forces them to “Do this in that place and at this particular time”.
Once the chicks start peeping in the nest the hormonal bath the hen brain is going through while brooding seems to lock her into those peeps and she’ll take good care of those particular chicks for a few weeks after hatching.
And btw don’t try stuffing a chick not brooded by a hen under her. She’ll kill the strange chick about 90% of the time.
What’s worse? If by any chance one of those non-broody hens happens to find a cracked egg in her nest and pecks at it out of curiosity and discovers it’s got egg inside that round lump? She’ll devour any egg she can peck a hole in from then on. And she’ll teach her flock mates to do the same.