I have had cats and horses for over 40 yrs and now chooks for about 3 yrs.We aren't putting too much DE in with them since we know it can be an irritant. We don't want to use any permethrine products since we have cats. We wouldn't be feeding them the garlic juice we are spraying it on them.
With it being caught early we are hoping to treat it right away preferably with stuff we have on hand.
The horse bug spray I use has permethrin in it and I have used it liberally on the horses, many times getting the cats sprayed also - cats never had issues. It was only when I got chooks and read here it is toxic to cats - who knew I was trying to kill my cats haha!
Anywhooo you will never get rid of those mites unless you use a proper product to eradicate them. This past summer I brought three pullets here who had lice and infected my gang. I used the horse bug spray, spraying under the wings and their bellies. I also sprayed the roosting and nesting boxes after removing all bedding. Repeated in two weeks and problem solved.
For you, I would do a quick spray under the wee ones wings, belly and especially their legs, make sure it gets to their skin. You can spray some on your hands (wear examination gloves if your chemical sensitive) and rub it on their legs etc if your worried about spraying.
Clean out the whole cage and get rid of the bedding, spray the cage and replace the bedding. Repeat in 2 weeks.
Any horse bug spray will do, I use a Canadian brand called Bronco spray, I am assuming you’re in the US so you can get a vastly greater variety down there.
Good luck! And you should post some photos of your babies I love seeing chickies