Why have my hens have stopped laying?

There can be several reasons why chickens have stopped laying, generally chickens stop laying when they go through a moult which is usually in late summer. They also need around 16 hours of daylight per day in order to lay and over the winter months they will usually stop laying. In the U.K. they normally stop from November to early March. Laying can continue through the use of artificial lighting to extend the natural daylight hours but there is controversy over whether this unnatural stimulation is natural. Some other factors that can stop a hen from laying are broodiness, illness, stress (for example when moved to a new environment)  incorrect diet (for example, a diet with insufficient protein or over feeding), lack of calcium or grit, lice, red mite, and even severe weather conditions.

A good starting point is to know how many eggs you can expect from your breed of chicken and more importantly the particular strain of bird you have. Generally, birds that have been highly bred for showing lay less eggs as they have been selected for looks rather than egg numbers.