Thanks Pat. I have used the Battles (bought the right one!) on them. Some worse than others, the bantam house unaffected so far and haven't seen any on the chicks. I am not really sure about quantities so rubbed plenty under the vents and some under the wings but really hard to find skin as some of them are so well feathered!
Do you know that place on a cat where you scratch and they start flicking with their back leg trying to scratch because it itches? Well, a couple of the hennies were doing that with their beaks! Poor girls, it must itch so much, when I rubbed the powder on, they started scratching with their beaks. Also, 2 of the Black Rocks had a small prolapse when they were caught (they are not used to that much handling and have never enjoyed it) so my son had the experience of rushing inside to get me a plastic bag and then watching me push it back in.... ah, what we do with these girls!