That reminds me of a story...
One day a woman was preparing her Thanksgiving Ham like she did every year. She prepared the ham by cutting off the top, and setting it aside before she placed the ham into the pot.
As her daughter watched her, she asked her mom why she cut the top off of the ham before putting it into the pot.
Her mom replied to her that this was how her own mom always did it, and she just figured it was how it was supposed to be done.
The young girl went to her grandmother, and asked her why she cut the top off of the ham before she put it into the pot.
Her grandmother's answer shook the foundations of family tradition. She replied to her granddaughter, "Well honey, it was the only way to make it fit into my pot."
The woman probably was told that they needed a certain number of chickens, because that was all the coop could handle. Her conclusion was that it had to do with luck of odd or even numbers.
Her parents probably didn't eat the fertilized eggs, because you don't eat the seed when you need it to grow the crop, and they were wanting more chickens.
She probably figured that feathers didn't grow back, because she never saw them grow back because the other chickens kept picking at that hen.
The moral of the story... Explain the details to your children so that they don't come to the wrong conclusions and grow up ignorant.