Symptoms: Sorry to re-start a thread that is all over this site. But, as so many others have found, there is so much conflicting information that I feel overwhelmed and paralyzed as to which route to take. Additionally, while there is a lot of advice, there seems to be little follow through. My birds seem mostly healthy and active. Four of the five adult hens have pale combs... 3 have recently moulted. 2 are only 33 weeks old and one of them is broody. The other is a bantam Mille Fleur D'uccle and she seems sad and lonely as I have lost several hens to predators this year including her boyfriend. Additionally, I have 5 chicks that are 9 weeks old. (Total number of birds is 10) They are free-ranging with the 5 adults and all is well with interactions but each group returns to their own familiar coop at night. I know that my hens have lice. I can see them. And one hen (Easter Egger) has some egg-cementing on the feather base. I have treated numerous times with DE (Diatamaceous Earth). I do believe that this works. The lice are always gone fairly quickly. But it must be repeated many times... I think once a week because there are always more hatching and the DE only kills ones it comes into contact with. The DE doesn't last and the new nits hatch and the cycle continues. I have also sprayed Poultry Protector in the coop when treating birds with DE. I have no way to know, but I suspect that I may have other parasites, as well. Perhaps mites? I see my chickens scratching even when I have repeated DE a few times and see no active crawling lice on their bodies. I understand mites are smaller and harder to see. I heard you might only see them at night. After dark when I check, I often see chickens scratching and sometimes shaking their heads but I don't see anything there when I look down in between their feathers. I have seen repeating of blood spots in one particular chicken's eggs (Black Copper Marans). Is this a symptom of internal parasites? Or is this just her? I also have one chicken with a very ragged tail (A different Easter Egger from the one with cemented lice eggs). I was concerned. Was she ratting her own tail because she was itchy? Was it damaged from parasites? Was it a sign she was starting to moult. Well, sure enough, she did moult. She has beautiful new feathers... EXCEPT the ratty tail feather. It never came out and still there looks more hideous than ever. Is this Depluming Mites? Solutions: I dusted birds with DE but if internal parasites, too, that won't help. I used Wazine in drinking water back in June (5 months ago) as I was suspicious there was a problem. I sprayed coop thoroughly with Poultry Protector. I bought Ivermectin Cattle Pour-on. But have been very hesitant to use it. I can't get consistent info on concentration of product with dosing. Some people dose with "drops" others use actual measurements but I am still thoroughly confused. Too little will cause resistance. Too much is harsh and potentially harmful. I like Kathy Mormino's youtube video on treating chickens with Elector PSP but wow, that stuff is expensive! I mostly appreciated that she really showed you start to finish how she does it so I think I could do this with confidence. I also like the youtube video on Ivermectin by SelfSufficientMe on Worms, Mites and lice but he doesn't tell the concentration of his ivermectin. What to do? Help, please. Thanks!