Let me start by asking following questions:

Q1. Why does the hen not know when to stop brooding? Mine keeps returning back to her nest even after taking away hatched eggs and none left.

Q2: Why do poults not know how to start feeding after several days it hatched? I force feed mine, only the resilient ones survive.
Q3: Why do hens occasionally take out some eggs with their beak from her nest? like using instinct to determine bad eggs.