At that point, you might choose to turn them into lunch or allow them to live out their days pecking around your back yard or like most people, you won't have the space for endless numbers of hens digging up your yard and you will want to 'retire' them and replace them with new layer hens.As keeping chickens becomes increasingly popular, the options for retiring old hens is also broadening as many cities now have traders who will take your old hens. Some place them with foster parents who have the space to let them run and lay when they feel like it. Others turn them into various kinds of foods for someone's table.
Dependent upon your world view, you may want to cross check with your chosen hen recycler regarding the hen's final destination.
Considerations for keeping hens are the amount of space you have, how many eggs you eat each week and how you will manage your hens while you are away on holidays. Most generic layer hens will lay an egg almost every day in the first year and then decrease by 20% the following year. Different breeds of hens live and lay longer. You simply need to find a balance between the practicality of the number of eggs you want, the space you have and the preferred 'look of your chook'.