Hens will not start laying eggs until they are about six months old, some hens may be older before they lay eggs. Once they have started, they will lay eggs for several months.
This is called the Laying Period.
Usually, hens start to lay one egg every day. After a few eggs (maybe 4 or 5) they may wait for two or three days before they lay the next egg. The laying period may last up too eleven or twelve months in some hens. Some hens may lay over 200 eggs in this period before they stop laying eggs and start to lose some of their feathers. This is quite natural and is the period called the Moult. The moult (or moulting period) will last several weeks (maybe 6 or 10 weeks).
After the moult, the hen will start laying eggs again. In this second laying period, she will lay fewer eggs than in the first laying period. She will only lay about three-quarter of the number. After this second laying period, there will be another moulting period. This change between laying and moulting could carry on for several years, but in each laying period, she will lay fewer eggs than in the one before. When she lays to few eggs, it is not profitable for the farmer to keep her. When it costs more to keep and feed her than the value of the eggs she is laying. This is usually at the end of the second laying period.
However, the farmer may decide that he cannot keep her after the first laying period. If he keeps her for the second laying, she will still need the same amount of food, but she will lay fewer eggs. So if the price of the chicken food is high, the farmer will think she is too expensive to keep. If the hen is too old to lay, she will go for meat. This is the type of hen that is called a boiling hen. Some of these hens will provide meat for the chicken pies that are sold in some shops.