We tried dusting - it was messy, I wasn't sure I was truly getting it under their wings and I was concerned about breathing the dust - even though I wore a mask.
After A LOT of research this is what we found and it truly works. It's fast and effective.
You need two things and preferably two people. 1) Ivermectin pour on for cattle (yes, I know you've got chickens - make sure it's the pour on and not the injectable) and 2) a medicine dropper (you can pick one up from your local pharmacy if you don't have one).
You can get the Ivermectin at your local
TSC or FFH.
Directions: If you're planning on having her hatch the eggs she's sitting on mark them before you start. If not, pull them out before you start.
Depending on the size of the birds (this is for the standard bird) put
one drop under each wing and one on the vent - make sure you get it on the skin. It won't work if you get it on the feathers. For bantams I did just under the wings. The best thing is to wait for them to roost. Have one person hold the bird and one person administer the medication. This will take care of
everything - lice, mites, worms, etc.
You only have to do this once.
We had an infestation of lice and after only one treatment they were gone when we checked a couple of days later. Ivermectin also transfers into the eggs so any they lay after you medicate will need to be destroyed. We did this for about 4 weeks just to be on the safe side.
It was also recommended to put natural wood ash (from a woodburning stove) where they dust. Supposedly this is a natural deterrent but my birds weren't impressed. Maybe in the winter when dirt is not so available they'll think differently.
Good luck
