Thank you Aart, it is a very good observation. We normally have a pretty good breeze where we are, thank goodness, and it helps with the mosquitos and the heat. Regarding the aromatic bits I am thinking about placing them in containers inside the run close to the coops on top of the rafters in the ceiling where the breeze, the sun and rain can't get and maybe they will last longer. I am discarding the idea of spreading them outside the perimeter of the chicken fence like I had originally planned thanks to you. The aromatic oils I have in small containers in the coops have to be renewed every 3 or 4 days because they dry out.
As far as the Bt bits, I think it is a good product. Right now I have standing water pretty much everywhere so it will help with the larvae until it dries (hopefully we are done with the storms). Sun is out and doing its job of drying. How long is it for larvae to turn into a blood sucking beasts? I read the mosquito life cycle some time ago, I need to read it again but my recollection is that it is not that many days 4 or 5 days???