It's something just about all chickens work and figure out- the pecking order. Now what exactly is the pecking order, is it necessary, and should you encourage it? First, lets take a look at what the pecking order is.
The pecking order is a ranking among chickens in a flock to see who is higher up in the order than others. Commonly, two chickens come up to each other, flare their feathers, bump into each other, and try to look tall, and the first one to walk off is lower in the pecking order than their opponent. Some chickens my come up to each other and one pecks at the other's head. If the opponent doesn't walk away, they peck at the other chicken's head too. Same thing, the first chicken to walk away is lower than their opponent. As long as no one is bleeding or hurt, this is fine and just part of a chicken's natural instinct. If they do get hurt, try to cover up the blood color or stop the bleeding. Applying cornstarch to the wound is proven to stop the bleeding and cover up the blood color.
The chickens towards the top (the ones that usually win a challenge against another chicken) usually eat first and get the treats first. The chickens toward the bottom of the pecking order eat whatever is left, or are chased away by the other chickens while trying to eat. The chickens toward the bottom of the pecking order eat after everyone is away from the food station, or some may even try and try again to eat with the others. The ones toward the bottom will also get pecked at near their tail area as a signal to move.
Here, two of my chickens have waited for the others to move so they can eat too.
So why have a pecking order?
A pecking order will bring peace to the flock, as they know their rankings and who eats first. The pecking order is most obvious in roosters and cockerels. The roosters and cockerels challenge each other also to see who is the protector and hens' rooster. The top rooster will typically be the one to crow, protect, find food for the girls, and fertilize the eggs.
However, some roosters and cockerels may try the pecking order on you, so be prepared. If they do, try to chase them away or push them away. I have had one that challenged me, and I would chase him away. He still wouldn't learn, and ended up hurting me. With roosters like that, you want to isolate them and monitor them for a few days. If you let them out and they do the same thing, try isolating them again. If they still don't learn even after a few times in isolation, then it may be time for him to go to the stew pot.
So how do I encourage the pecking order?
It's pretty simple. If you notice someone challenging another chicken, just let them challenge each other. Some will get hurt, but it is normal. If one chicken targets all the others and hurts them for no reason, isolate her or him for a few days. But as long as it's just chickens figuring out where they rank, everything is fine. It is in their natural instincts, so why eliminate some of their natural instincts by breaking them up if they are challenging each other? Basically, as long as no one is targeting and severely hurting the others, let it happen. After a couple or few weeks of them doing this, they'll know where they rank and all will be well.