FREAKING OUT!!!! MITES! on new chicks

So here's the situation! I have had chickens for just over 1 year now. 3 weeks ago, I let 2 Silkies sit on eggs. I discovered today that 5 have hatched. Unfortunately, I also, discovered mites crawling all over me after picking up my girls and their new babies. I have had them in a nesting box, (a plastic kitty litter box) in a wire dog kennel since they went broody. At first it was sitting in the coop but I moved it out when the other chickens started roosting on it and thus pooping on everything in the kennel. They are now in their nesting box in an old crib covered in wire at first just outside the coop on a concrete walkway and as of today, in a separate pen with the duck brooder, . I have over 60+ chickens of varying ages in the building. I only have nesting boxes in the area with my layers. I have a section with 11 week olds and a section with 7/8 week olds. None of them mix. I, also, have a brooder in the same building with 1 week old ducks in it. I have never seen any bugs until today and we handle our chickens multiple times a day.

So here is a list of questions:
1. Where and who do I treat? The whole building? The roosts ( plastic utility shelves), nesting boxes? All of my chickens? Just the broodys with their chicks and their nesting box and maternity pen?

2. What do I treat with that is safe for every age including the newly hatched? I have heard DE but then there are others that say no due to respiratory issues with the chickens.

3. Can these mites infest other animals, including us and our home?

4. Do ducks get these and should I treat them also?

Any help is appreciated!!!!

I just checked the vents on my adult chickens. They look healthy and clean.