If you're guinea keets and adult chickens are mingling now, make sure you know that the keets are getting enough food. My 12 wk old keets have been in a run with my 15 wk old chicks for a few days now and the chicks do pick on the guinea keets. There are also two other chicks, about 7 wks old, which have lived with the guineas for most of their lives. These two younger chicks get bullied a lot by the older chicks, but they are able to eat fine with the guinea keets. (because they've bonded together) I would definitely make sure that your hens aren't bullying the keets too much. (I don't know what breed your chickens are, but there must be quite a size difference between them and the guinea keets.)
Good luck!
Good luck!
