Thank you for the advice - I would rather keep them free ranging, I've had them confined for 3 days now and they seem unhappy in spite of a big log to play on, a horse ball with some feed in and fresh greens hung up (all ignored). They don't appear to be eating much except a bit of corn that I scatter for them in the afternoon. The friend who advised keeping them shut in has had a lifetime in farming and is generally very knowledgable, but on this one I think I'll follow my own instincts. The only problem I can see is how to stop the hens eating their growers pellets, but I could leave the bottom door of their shed closed and open the top, so that they can fly out.