I'm not seeing either of the usual signs of mites/lice on my birds, meaning I've never seen any visible black or red specks crawling on them or in their cage, and neither bird has missing feathers from excessive scratching. I don't believe either bird is scratching, preening or ruffling its feathers excessively, although I'm not sure I would know what excessive really is. How often is TOO often? They also do not seem to be any more restless than usual. However, they've always scratched, preened and ruffled their feathers now and then throughout the day, and I've always considered this normal.
Suddenly a week or so ago, I happened to notice a tiny little almost-microscopic light-gray speck crawling around on a white paper on my desk, which is located just 3 feet from the birds' cage. I wondered then if it could be a bird mite and almost treated the birds with a mite spray, but after I looked carefully around my desk, and around the cage vicinity, and couldn't find any more, I decided it must have been a false alarm.
I had almost forgotten about it, until several days later when I noticed that I was suddenly feeling odd crawling sensations on my skin -- particularly my ankles, face and scalp. I could never find anything on my skin after looking, yet I knew there had to be something there. Occasionally there also would be a feeling of something biting, though this was less often. Yesterday I used a pet shampoo designed to kill mites on cats and dogs, and that seemed to instantly stop the crawling and biting sensations...I've had no more at all, so far. I also carefully cleaned around my desk and the cage area, just in case...though I was afraid to use anything stronger than household soap and water to avoid harming the birds' respiratory systems.
So today I looked carefully around my desk again, and found 2 more of the exact same little gray specks crawling on a paper on my desk. My desk area has much better lighting than the floor near the cage, and the white paper provided an ideal background for me to easily see them, whereas they tend to blend in much more easily with my brown flooring. So these little specks -- whatever they are -- would show up much better on my desk than anywhere else near the cage.
Now I'm facing the very real possibility that my entire home may need to be fumigated against these things, depending on how far from the cage they have managed to migrate.
I've scheduled a pest exterminator to take a look later this week. He's asked me by phone to "catch" one of these things for them to examine, but they are so very tiny I'm not sure how I would manage to do that without smashing them.I'm absolutely convinced that whatever these specks are, they have to have originated from the birds, as anyone who knows me would consider my own personal cleanliness and hygiene to be quite obsessive.
I've never had any issues at all with that, nor had I ever found any such little specks in my home until now. I'm suspecting my hen may have become infested during a visit to the vet 2 months ago -- the only time either bird has been out of my home while I've had them.My questions:
1) How often is considered "excessive" when it comes to birds scratching or preening?
2) Is it possible for birds to have mites/lice without showing any visible plumage problems?
3) How easy is it to rid birds, along with their cage (and apparently my home) if infested with bird mites/lice?
4) Would spraying their nest (including nesting material) pose any harm to the birds or to any hatchlings that appear in the coming weeks?
My birds currently are building a new nest in a larger nestbox I recently installed. When I installed the nest, I already had decided the mite scare was a false alarm, but for preventive purposes -- just in case -- I did treat the bottom of the wooden box with a mite spray before adding a paper towel and nesting material. I'm now realizing I probably need to spray the entire nest they're building before my hen begins laying eggs again in the coming days.
Has anyone else ever had issues with bird mites/lice migrating into their homes, and how have you dealt with this problem to safely eliminate it without harming the birds?
Never heard of paper mites 
And if so, I'll be greatly relieved. I'll definitely ask the exterminator about it when he comes, and try Meep's excellent tape idea.
Well, this is one perpetually annoying sensation I would never wish upon my worst enemy -- let alone someone I respect as much as you, Candace! And while the idea of paper mites is infinitely less bothersome than that of a bird-mite infestation, for a self-confessed OCD sufferer such as myself, it can still prompt one to feel the need to fumigate. 
I hear you... sorry for the itchy imagery, Candace -- I remember watching 'Arachnaphobia' and feeling for a long time afterward that a spider might be crawling on me somewhere. 