Quote: I agree. It absolutely works. Ivermectin, permethrin, and frontline all contain the appropriate chemicals to terminate lice (& fleas) by eliminating their ability to reproduce and/or decreasing the current infestation. I brought an injured chick into an avian vet a couple months ago, and received quite an education on how to eliminate mites in poultry. The vet told me to use ivermectin, but be aware of user error. Do your math! A tiny bantam is not going to respond the same way as LF. Really weigh your birds, and double check your math when it comes to dosage. The vet looked me right in the eye & warned me that she'd seen "mistakes" with folks in the past who have applied too much. That's strictly user error if you're using something that is off label. Those products definitely work!
I am by no means an expert, but I have use DE in my coops as a preventative with great results. I have also used Sevin when I brought in a new coop & was worried about a potential mite infestation. Easy.
The only issue is the percentage that you use during your application, and due diligence after the fact. Keep up with the treatment, on the birds and in the coop. It's a pain-- but once you go through the process you realize how much an ounce of prevention is worth...