Spraying them at night does make it easier.I will try that, do I have to spray it on them everywhere on their bodies? because its easier to do it when they sleep I can spray under them and on there sides please more details, and I use the one that mixes with water I make is stronger then the recommendation mix cuz I feel its not working so good, do ducks get mites as well?
I am not sure about ducks...I would guess that yes they do get bugs too.

Be sure to spray the entire coop...all the cracks and crevices too.
If I were you I would treat the coop and birds once a week until the mites are gone.
Notice on the sheet I linked above that mites can live off of the birds for 3 WEEKS. During those 3 weeks they are constantly making babies.