Chickens, when kept in a reasonably stable environment, have a lifespan of 5 to 7 years. Chickens cared for as pets can live for over 10 years, while chickens caged for egg hatching may only have a lifespan of 2 years or under.
Chickens are often reared for meat or eggs, rendering them as broiler chickens or egg-laying hens, respectively. Sometimes hen are reinvigorated, meaning that they are forced to be without water or food for days, in order to restart egg-laying. Egg production of egg-laying chickens decreases yearly. A hen's egg production can decrease by up to 10 percent each year that she ages.