Don't ever listen to exterminators. Everything they do is toxic. For mites--in fact for any insects including spiders and ants--simply use DIATOMACEOUS EARTH (pronounced DYE-at-oh-MAY-shuss).
I'm a bird Mom of 36 years and an animal lover and rescuer even longer: since the age of two. Diatomaceous earth is not, contrary to what the name would lead you to believe, "earth". It has nothing to do with soil. It's natural, pulverized exoskeletons of tiny marine animals. When an insect eats this powder, it desiccates them--dries them out inside, depriving them of moisture--and cuts them so that the insects die.
There are 2 kinds of diatomaceous earth: the kind for industrial use which you put outside on the ground, in your trash cans to prevent ants, flies and other insects, etc. and the edible kind which humans use as nutritional supplements for themselves and their pets. The only difference in manufacturing is not in the diatomaceous earth but in the equipment they use. DO NOT EVER USE industrial diatomaceous earth on your animals or yourself because the equipment can be tainted with pesticides and other poisons.
Diatomaceous earth is available at feed stores, hardware stores, online. Of course, the edible kind is more expensive.
Just dust your birdies with diatomaceous earth and the mites will exit rapidly. Get it under the feathers and massage into their skin underneath their insulation feathers which are right next to their skin and look like puffy little snowflakes.
Mites can eventually kill birds and infect their blood. It's a very serious infestation.
Here's one of my personal experiences with diatomaceous earth. My Mom got an infestation of carpenter ants which burrowed through the exterior brick wall of her home and set up residence inside her curtain rods. When I opened the curtain rod it was filled with what looked like black sand. Every inch of space was filled with hundreds of thousands of ants. I poured them out, vacuumed them up (immediately placing the vacuum's dust bag in the outside garbage cans inside double-knotte plastic) and dusted the hollow interior of the rods with diatomaceous earth. Then I got industrial diatomaceous earth "umbrella" (they're covered to prevent rain from washing them away) stands at a hardware store to place in the ground at the base of the home's exterior. I pumped the powder (they have dispensers for that) into crevices of the brick exterior and onto exterior window sills inside and outside of the house, and into the ant houses. I also pumped it into the interior floor spaces between the baseboards and the floor.
Result? Within TWO HOURS NO MORE ANTS! EVER! (Of course, depending upon your situation you might need to reapply annually.)
So, please protect yourselves, our earth, our dear animals, and your home environment from toxins and use non-toxic DIATOMACEOUS EARTH.
Inside the home if you have babies or children or pets crawling around, use the edible diatomaceous earth to apply to the baseboard areas. I used to have horses and I would apply that around the stable and to them and no more flies. Sprinkle diatomaceous earth into your garbage cans (do keep your cans clean with a liner and sprinkle the diatomaceous earth underneath the liner). The stuff is magic and SAFE! I imagine if you order edible diatomaceous earth in a huge quantity the price can be reduced. I always keep both the edible and the industrial diatomaceous earth around the house ready to be applied.
I'm sorry I saw this post so long after it was put online. Good luck to everyone from this lifelong city kid and animal lover! Let me know how it turns out.