Chickens take their pecking order very seriously. As flock animals, they adhere to a very strict social hierarchy and establishing a pecking order actually helps to keep peace in a flock. Being high in the order equates to being "big man or woman on campus" and enjoying the top roost at night, first dibs on food and treats, the rooster's attention, and even the prime spot in the sun to take a dust bath.
Chickens continually remind the others where they stand in the social order. The alpha hen at the top can peck at everyone, the hen just below her in the pecking order can assert her dominance on any flock member except the alpha hen, and so on down the line until you reach the bottom. The poor hen on the bottom often becomes everyone's whipping boy. So while it's natural to feel badly for the hen who's lowest on the totem pole, it is very normal within every chicken flock.
After watching my chickens for years, and being fascinated by their social interaction, I have learned a few things. One thing I discovered early on is that the rooster isn't always at the top of the pecking order. It's often an alpha hen - possibly leading to the phrase "hen-pecked" when describing a man whose wife is clearly in charge!
Pecking order doesn't always go from largest to smallest either. Anyone who has ever raised a big, gentle breed like an Orpington or Cochin knows that they are rarely at the top of the order. Age rarely plays a part in the exact order either, often a newly mature hen will begin to challenge those above her. I've also observed that my chickens tend to socialize with those who are close to them in the pecking order.
So a clique of the more assertive hens will usually hang out together during free range time, roost together at night on the highest bars, and eat and take dust baths together while those lower on the pecking order will spend time together. Kind of like high school and not being welcome at the popular kids lunch table!
Usually once a flock has sorted out the order and everyone knows their place, skirmishes will be infrequent and everyone will get along, but even so, minor taps on the head on occasion is pretty normal even in a happy, well-adjusted flock. Often when especially yummy treats are offered, a hen higher in the pecking order will make a move to peck at those lower in the order who attempt to eat before she's done, sometimes not even needing to make actual physical contact to make her point. And sometimes the order can change when a younger chicken reaching maturity decides to challenge an older hen above her.
Because chickens do take the pecking order so seriously, and any newcomer means more competition for their spot in the pecking order and position within the flock, adding more chickens to a flock can be a tricky proposition. Care and patience needs to be used whenever you're
integrating new flock members, and any time you add or remove chickens (due to rehoming or death).
If your chickens sense weakness - whether its due to an injury, age or sickness (they will often sense a weaker or ailing hen well before you do and start picking on her) - that can also cause a shift in the pecking order. And in fact, if you all of a sudden notice a clear shift in the order or one chicken being pecked, it's a good idea to check her over carefully for injury and watch her for signs of illness.
Mother hens use "tough love" to teach their chicks how the pecking order works at an early age. When they are about 5 weeks old, she will start shooing them away from her, even pecking them gently on the head if they approach the feed while she's eating or try to roost with her. This is normal and shouldn't last for more than a few days. What she's doing is showing them their place in the flock.
Pecking order "reprimands" are usually concentrated to the head and neck area, while bullying and feather picking can occur around the tail and vent area. Generally,
it's best to stand back and let your chickens sort their pecking order out on their own - although if blood is drawn or the pecking is relentless, it might be time to step in. At that point
you might be dealing with a bully who needs to be removed from the flock for a few days.
Interestingly, studies seem to show that chickens are able to remember their place in a pecking order when there are 30 or fewer chickens in the flock. Once the flow grows larger than that, they tend to get confused and pecking order issues can be more common. But for the small backyard flock, once the initial order is determined, your chickens should all exist in harmony with each other.
