I keep Permethrin concentrate on hand so I can just add water and spray from a water bottle, or mix with shampoo, whatever. But for long lasting effect as an area spray in the yard, and in the coop, I use Bifen XTS. And if something is living in hard to reach spaces, like between the walls, I use a fogger to ensure total coverage (I just mix concentrate with Kerosene, instead of buying expensive fogging chemicals).
Amazon is where I get my insecticides. You can easily get Permethrin-10 and the likes from your local
tractor supply store if you're in a hurry and don't care about saving money, or buy special sprays/shampoos at any store (they all contain Permethrin pretty much). Finding Bifenthrin locally isn't likely, as it is more of a professional exterminator product. Also be aware that, while Bifenthrin is approved for chicken coops (and yards) in most of the USA, it may be banned in Europe. The reason Bifen is banned in some places is because it kills aquatic critters, so never spray it within 10ft of any body of water! Bifen is safe for animals if allowed to dry completely before they return. Do not use Bifenthrin directly on animals, Permethrin is best for direct applications.
So, to summarize, if you treat your animal with Permethrin (Flea and tick spray or shampoo is the same thing), and spray your grounds/building(s) with Bifenthrin, then there won't be any bugs of any kind for about a month. Once things are under control, you can probably just go back to using DE and Sevin. Pretty simple really. The hardest part is learning the information above, which took me weeks of studying. Bifenthrin is really the key, because has a month long residual effect, killing any offspring or new arrivals. Permethrin has virtually no residual, so if you use it as an area spray, you'll have to repeat once a week or more, which can be frustrating.
