My Cochin hen has a case of either lice or mites (can they be white?) crawling on the spines of her abundant feathers. Some of her mixed breed batch of four-week-old chicks are showing them on their feathers as well. I've treated the hen with Permethrin-based poultry dust twice this week and did a small dust of the chicks. I still keep finding the things on their feathers. They run loose during the day and are caged at night. I dump the bedding from the cage whenever I dust. Is the dust safe for young chicks? I'm at wit's end with this. I appreciate any suggestions.