Once you have red mite in the house the best solution is ..... a match! They float on the breeze, you spread them yourself so always visit a house with red mite last, whether opening up, topping up water and feed or closing up at night. Have individual henhouses as far away from each other as possible. If they get on you they'll make their way up to your scalp (warmer there). Just wait a couple of hours then wash your hair. (Of course you may also wish to shower, bearing in mind the route they'll have take to get there!)
One of our projects for this Autumn is to design and build henhouses which are less likely to harbour red mite but which are cheap and simple enough to be burned without a pang of regret if they get infested.