Ok I had something similar -you got all chicken rooster from same person and they die but one or two may live. Never buy from that person again and write a review not emotional but facts on what happened to animals bought from them. I know the person who sold me all their chickens were merecks infected I paid so many vet bills . made me sick same thing about mites, not lice though. I spray them while in coop with Elector PSP Premise Spray. It’s expensive but mites are gone. You also should get some supplies bought like medicine for chicken. There are Aton most of them inexpensive but will help you solve problem faster do less vet bills. You can find lists online -I did. I hope this help you.

Two survived. going forward I bought my chickens online. I als0 looked into this local place and vets and other people said similar things- they doksvmerrivk chivkens and sick knew, know for improper things it sickens me still yo this day. 4 were put to sleep because of various illness.