They start to break down (mentally); they like do things that you wouldn't expect from a hen. They just flat-out change.
Pictures do show the signs of old age, if you look at a picture of yourself 10 years ago, you will see a change.
It depends on how old the hen is.
Five year old hens are not uncommon. She will not likely be producing any eggs at this age. She can be used for a brood hen or a pet.
127 years old
A hen generally shows old age when she is starting to loose feathers, and looks old. Her skin loses a little bit of colour, and she is not as active as she used to be. Her comb can go 'floppy' and loses colour also. These might also be symptoms of a type of bird disease also, so be careful in determining which is which. If it is a bird disease, she will become even more inactive, and will tend to lose her appetite.
A stewing hen refers to an old hen, usually over one year old. They tend to become tough as they age. The meat can become stringy if it is not cooked for a very long time.
Hens are called PULLETS prior to reaching a year old.
There's no exact age for a hen to die. They usually live up to 6 to 8 years.
A hen that is 5 month old is called a pullet. She is generally not as large as the full grown hen, usually slimmer, and her comb and wattles may not be full sized yet. Here is a website that will show you the progression from Hatch to 1 year.
Cluck Old Hen was created in 1923.
Most hens will begin laying eggs at 6 months of age. If you want to hatch these eggs the hen must have been with a rooster. There is no danger in breeding a hen too early unless the rooster is overly agressive.
11 years is the starting age. You mad not yet show signs. If you are a boy there will be increase in the size of testis. If girl, you will start menstruating.