Maybe I'm confusing your use of 'feather lice' with 'feather mites'(which are 'invisible' as they live inside the feather shaft-from what I've read)
So one day to kill live on peas...how many days for chickens?
Again wonders if chickens metabolized it (spread to skin) slower than peas?
Maybe I should have said poultry lice... Bugs seen were lice.
I think maybe that the type of lice that the peacock had drink from the eyes, so maybe that's why it worked faster on him?
They are a different type. I'll see if I can get some pictures of them.