Hen pecking/Cannibalism

"Birds will show cannibalistic behavior when they are crowded or feed-restricted. Flock behavior and inter-bird dynamics often include aggression of birds toward each other, which can ultimately result in injury. Cannibalism is a separate problem that may occur long after dominance relationships have been established. Cannibalism differs from dominance as it actually causes physical harm. Cannibalism may begin with feather pecking and is usually directed toward the body, toes, tail and the vent area. Prevention of cannibalism is much easier than treatment."


Overcrowding- You need to increase amount of space for each chicken, so they are able to escape being pecked
Not enough water/feed- Be sure all chickens have access at all times, they drink a lot of water so provide extra water bowls with fresh water daily 
Bright lights- If you have bright lights in the coop or run, keep the light intensity low to decrease extra activity/cannibalism 
Too hot- Keep the coop/run ventilated and cool, hot temperatures aggrivate them 
Nutrition deficiency- Deficiencies of nutrients like methionine, protein, and salt will increase a craving for feathers and blood 
External parasites- Regularly treat your chickens if they have lice/mites/etc. The parasites will encourage them to peck/injure skin 
Sick/small/weak chickens- Remove all sick, weak or small chickens, the dominant chickens will attack them
Hard ground- Your chickens need to scratch, dig, take dust bathes, etc. A hard surface will prevent them from doing this and keep them less occupied. I put mulch, mowed grass (fertilizer free), leaves, and loose dirt. I also spread seeds around for them to find. Do not use gravel or hay (hay will attract mites/lice)

I have not personally experienced cannibalism with my chickens, but I know a few others who have chickens that have hen pecked each other (to the death) because of too small of a space. Chickens are made to roam and forage in order to find food. Even if they are getting enough food for the day, they will still want to forage. If they can't they will get bored and beat up on each other (which is the same with all animals). The main thing to remember is to keep them in as natural a habitat as possible, which will give them space to roam, escape pecking, and be occupied.

This link shows pecked chickens, and a way to treat it:
This link shows how to make chicken "capes" to cover their injury:



Edith molting
If you notice your chickens are losing lots of feathers, most likely they are molting. If they are healthy, and if it's around winter time. The chicken's first year is always a little awkward, so they may not molt, or just a bit, or like my hen Edith, a full body molt every year. During this time, they will either decrease laying eggs, or stop until they have completely recovered. You will also know when they are not laying because their comb will be pink and dry, instead of thick and red when they are laying.
(They are NOT molting if you see damaged feathers/scabs/skin/blood on their back or head; then they are being hen pecked).
after the molt
Make sure there aren't any drafts in the coop, since their loss of feathers won't keep them as warm. One of my hens would sleep in the nesting box sometimes. If your hen/s seem cold and shaky, then you may need to put a heater in the coop or if its just one or two, you can put them inside the house, in a draft free room for the night so they don't get sick.
Molting is a very interesting process to watch. My girls actually seem embarrassed, and don't want me to come anywhere near them! They also don't feel great either, so I just leave them be. Then around a month later, they will be as good as new (literally) with pretty soft feathers.