So here is Neige, 3 weeks and two days into being broody. She continued like this for another week before I took action. She had no eggs under her but day after day continued to sit, sit, sit. It's a hormonal thing. I had to lift her off the nest each day to make sure she had a drink and something to eat but as soon as she'd had a wee peck she went straight back to the nest. Her comb began to lose its red colouring and became pale so I knew that I had to intervene or she would lose so much condition that she would die. So I put her in an empty cat cage for 24 hours, still in the hen house but with air circulating under her and no cosy nest. It felt so mean but it seemed to do the trick as the following day when she was let out she went off with the other hens ... for two hours then she was back on the nest again. So in the cage she went again for another 24 hours. Out she came, off she went, two hours later back on the nest. So I took the entire nest box with Neige in it outside, sat her next to the cat cage, told her that she'd be back in there if she didn't buck her ideas up. She listened, squawked then fluffed her feathers, got up and didn't get back on the nest again to be broody anymore. Phew.
We live and learn. I hated doing the cage thing. It really brought home the vile practise of caging hens for commercial gain and I really felt sorry for all the battery hens that are caged like that all their life just so that folk can have cheap eggs. The next time we will get fertilised eggs for them to sit on and hatch (we don't currently have a cockrel to fertilise ours). That would ensure only a 3 week sit and then Mrs Broody will become a happy mum.