Hens have stopped laying for a while now...

[IvyHybrid16]

My hens are about three years old and they stopped laying a year ago, any ideas as to why? They have full access to grass, water, layers pellets, corn etc etc but haven't laid an egg in ages and I'm worried that when I introduce my new hen they will be out if habit and try to eat the eggs she lays, any ideas?

 

[sumi]

They stopped a year ago? You have more patience than most, I think! Have a look here, this may help you figure it out:

https://www.backyardchickens.com/a/chicken-behaviours-and-egg-laying-why-are-my-hens-not-laying