By the time I realized that my chicks had mites, the smallest one was very lethargic and not eating much. She just laid down and then we could see the mites on her. When we checked the other chicks, they had mites under their wings and some of them on their heads. They might have had them in their vent area, also. I bought some Scalex Mite & Lice Spray for Birds at Petsmart. I figured if it was safe for aviary birds, it should be okay for the chicks. It killed the mites on contact. I cleaned everything in the brooder and actually moved them into a new brooder. They have not been outside since then. I will need to treat them and their brooder again at least 1 more time. I do think that this one chick with the eye problems also had mites in his/her ears. She/he would scratch them and almost fall over. I took a Q-tip, dipped it in the Scalex and swabbed her ears as well as I could. I did this a few times and she stopped scratching her ears. There are lots of threads on BYC dealing with mites. Just search for mites and you will pull up hours worth of reading material!