I have a hen with one-week old chicks. While she was setting, I checked her for mites. I checked her again yesterday, and while I saw no mites, I thought I saw some lice eggs. (She is white and was rather squirmy, so I will check again in the morning to be sure.) At any rate, she is somewhat "unthrifty."
If she does have mites or lice, what would be the best way to treat her without causing any ill effects to the chicks? I conducted a search and did not find much on this topic. I handle the chicks every day, and they seem to be fine so far. I've read that some people use pet store spray (either bird or dog and cat) and others use Sevin powder for taking care of the lice. I have some powder from the feed store that has worked for mites in the past. But what would be both effective and safe with the chicks?
I currently have mom and chicks in my greenhouse in the large plastic tub I use for a brooder. Temperatures were quite low for several days, but now that they are above freezing, I will be moving them to my small coop. I will give them a new cardboard nesting box with clean shavings. I do have diatomaceous earth and can dust the coop, but am dubious about the effectiveness of dusting the hen with it if she already has lice. I'll add a box of sand for dust-bathing too, but it's still too cold for any of them to wander too far from the nest box.