First of all, let me say that I have used Frontline on my chickens as a "just in case" measure, so I don't know if it actually kills the mites and lice. My daughter was a Manufacture's Representative for the Company that manufactures Frontline, and knows the product inside and out. Without repeating all the scientific stuff, she says that the oil glandS are instrumental in distributing Frontline through the animals skin. My question is...since chickens only have ONE oil gland, how does it work on them??? How is it distributed to all the areas of the chickens' bodies?