Ever heard of chicken sexting? It’s actually pretty fascinating. When chicks are hatched they need to be sorted between males and females, but there is no way to tell which are which, unless you are a professional chicken sexter.
You see, no one who sexes chickens can tell you how they determine the sex. They just know. You become a chicken sexter through the following training:
You pick up a chick
You look at it and say male or female
The chicken sexter who already knows how to tell says yes or no
You keep doing that until you always (or most always) get the answer right.
You are knighted Professional Chicken Sexter