It's called "the moult" (US molt) - and it's nothing to worry about.
What is moulting and what happens?
If you have dogs, you'll know all about moulting. It's very much the same with chickens: it happens when the chicken's old feathers are shed, and new plumage grows.
It's an entirely natural process which applies to both males and females, and it normally happens once a year, as summer fades into autumn.
When the days start getting shorter and weather starts cooling down, it's a sign to our flock: out with the old, in with the new! Hormones are triggered and the moult begins.
The bird will start to lose feathers at the head, then down its back, sides and thighs and finally, tail feathers are shed. It can be a sorry sight, and new chicken owners can be pretty fazed by it.
But it's seriously nothing to worry about - and there are things we can do to help.
When a chicken is about to start moulting, you may notice that plumage looks very dull and dry. You're also likely to see...
You may hear these terms bandied around the web. A backyard chicken may have either a hard or soft moult.
A Hard moult is when the hen (or rooster - it can happen to either) looks seriously unwell. She will lose almost all her feathers very quickly, so she'll look almost bald, and have large areas of skin visible.
A soft moult is when the chickens don't lose very much plumage at all. They'll look a bit ragged, and the tail will probably be missing, but they won't look anything like as bad as a chicken going through a hard moult.
A forced moult is illegal in the European Union, but sadly is still very common in commercial egg factory farms in the US(1).
It involves forcing the hens to moult by stressing their bodies. Food is withheld for between 7 and 14 days. Sometimes, water is also witheld. The hens all go into moult at the same time.
Although their egg-laying stops during the moult, the theory is that giving their reproductive system a rest for a couple of weeks, hens will keep laying for longer than the usual 12 months allowed in commercial production.
Systematic starvation of chickens is inhumane, and many birds die during forced moult because their immune system is depleted. That can make them - and their eggs - susceptible to salmonella.
You'll have heard of a dog moulting to grow its winter coat; it's very much the same for chickens. During the course of a year, the plumage becomes dull and shabby. Feathers break, and although this doesn't much matter in the summer months, by the time winter arrives the feathers aren't able to insulate the chicken properly from the cold weather.
Moulting is a natural process that allows those old feathers to be shed and a new coat to be grown. It also allows time for their reproductive organs to rest.
You won't necessarily notice, but once a chicken has moulted and grown her new coat you'll see a big difference. The new coat will be glossy and perfectly formed, covering the skin and protecting from wind, rain and frost.
If you have a rooster, you may well also see hens lose plumage if they are "well used". Feathers are pulled off by the male digging his claws and spurs into the hen, and hanging onto her back with his beak.
Don't mistake this for moulting.
A chicken may also moult when they're stressed, but won't usually lose all her feathers - you're more likely to see bald patches.
And finally, a broody hen may moult once her chicks are independent and she's settling back into her egg-laying cycle.
Losing their plumage is not painful. Feathers fall out exactly like a human's hair does.
Re-growth in its early stages, though, can be painful and it's best to handle your chickens as little as possible during this time. If you need to handle them, do it very gently.
The reason? "Pin feathers", also sometimes called "blood feathers", are the start of feathers growing again. Your chicken will begin to look a bit like a porcupine as these small quills emerge.
This is a photo of one of my Wyandotte hens as she began growing back her feathering. See how the short "pin" or "blood" feathers are dark?
That's because, at this stage, they're full of blood and although feathers themselves don't have nerves, the point at which the feathers emerge do.(3) So touching or putting pressure on the quills, hurts.
And they'll stay at this stage for about 5 days before the quill begins to flake off and the feather grows.
If they're handled roughly, or if the pin feathers are pecked or damaged in any way, the chicken will bleed - and they can bleed quite profusely.
If you see a chicken with bloodied feathering or skin - during the moult or not - you'll need to deal with it immediately. Chickens are ruthless. They're attracted by the colour red, and they'll peck at blood on other members of the flock, sometimes literally to the death.
Check your chicken over for damage. If it's damage to one or two pin feathers, use a cleanser such as Vetericyn first...
...and then cover the wound with Blue-Kote, which disguises the colour red. That reduces the chances that the chicken will continue to be pecked.
But make sure you keep checking, just in case. And if the pecking worsens or the damage is more extensive, remove the chicken into isolation until she's healed completely. For a detailed explanation of how and when to isolate, see this page.
Wing feathers, like all other plumage, falls off when a chicken moults, and the wings then grow back to their normal length.
So you need to assess the situation: is this a chicken who is likely to continue to fly into danger?
If so, you will need to clip her wings again. Be very careful not to clip while the pin feathers are still growing, though - they're full of blood and you'll cause pain. Feathers which are fully grown will be either white, or clear. Don't do it when they're dark.
Find out how to do clip wings without harming your chickens, here.
The short answer is "no". At best, egg-laying will slow down - my Red Stars sometimes carry on laying occasionally during the moult - but for most hens it will stop altogether.
In order to make a whole covering of feathers, chickens must keep all the protein they can get to prioritise their new plumage.
So the protein their bodies extract from food is diverted from egg-laying to feather-growing - and so they stop laying eggs.
Given the information in the preceding section, it's probably fairly obvious that what chickens need when they're moulting is extra protein.
Chickens are more astute than a lot of people give them credit for - they known instinctively what they need, and how to get it. So if your flock doesn't get enough protein during the moult, there's a danger that they'll start pecking at what's left of each other's feathers instead.
But it needs to be the right sort of protein. Many high protein foods are also high in fat, and it's known that too much can lead to Sudden Chicken Death Syndrome.
So don't overdo it. High protein treats should constitute no more than 10% of the flock's daily food, and it should be given when the moult begins, and stop no more than two weeks after.
It's possible to buy a commercially-made high-protein food like this one...
which also has additional vitamins and minerals.
Less expensive sources of protein include...
For more high protein foods that are actually good for your flock, see this article.
Obviously, your chickens will need water during the moult, and it's a good idea to add some Apple Cider Vinegar (ACV) at the rate of 20 mls to one litre (about one tablespoon to a gallon) of water.
It's full of vitamins and minerals, and also acts as a very mild anti-bacterial agent.(5)
It must be raw, unpasteurised ACV though, and include the "mother" - vinegar which is not will actually kill the helpful bacteria.
There are several good brands out there, and it will be cheaper at your local feed store than online. This is the brand I use...
...and it's never let me down.
Don't use it in metal waterers, though - it will erode the metal.
A lot of "facts" you'll find on the internet are often people's individual views, based on inaccurate information repeated from poor quality sources.
The information I provide in this article and others is based not just on my own experience, but on evidenced facts from scientific, peer-reviewed research and highly respected and experienced poultry keepers such as Gail Damerow.
Some of the sources I have used in this article are these.
1. McCowan B, et al: Effects of Induced molting on the well-being of egg-laying hens. Pub. Journal of Applied Animal Welfare Science, 2006.
2. Nasir Rajput et al: Comparative Study on the Pre-molting Performance of Different Strains of White Leghorn Layers. Pub. Poultry Industry, 2017.
3. Mingke, Y, et al: The developmental biology of feather follicles. Pub. Department of Pathology, Cell and Neurobiology, University of Southern California.
4. Gupta, A, et al: "Extraction of Keratin Protein from Chicken Feathers". Pub. Faculty of Chemical and Natural Resources Engineering, University of Malaysia.
5. Hayajneh, F, et al: Anticoccidial Effect of Apple Cider Vinegar on Broiler Chicken: An Organic Treatment to Measure Anti-oxidant Effect. Pub Polish Journal of Veterinary Sciences, 2018.