Mites come out at night but the fleas will attach to the birds usually on their heads as in the picture you posted in an earlier post. I use a headlamp so I have my hands free and go out to the coops after the birds roost and check the birds. Maybe you have mites too. I have used permethrin spray when I had an infestation. It takes at least 3 weekly application of thoroughly spraying the inside of the coop. Every crack and crevice where mites can hide, nest boxes, on and under the roosts, everywhere. It does not kill the mite eggs so repeated 3 or 4 weekly treatments are necessary and there is no egg withdrawal period. I use the permethrin poultry dust in the nest boxes. I have tried a lot of different things. I use permethrin. It works. If you have a TSC they carry the permethrin powder, the premixed spray bottles and the concentrate. Good luck...