It could be cheyletiella mite. They are microscopic bugs. You can catch them through an animal or a place you visited that had animals and they can multiply in your home. I struggled with this bug for over a year and finally identified the bug. If you have dogs or cats, check the tops of their coat along the neck and back, if they have dandruff, give them a bath and wash this dandruff off well, if the dandruff keeps appearing and not washing off then you have cheyletiella mites aka "walking dandruff". Get your dogs "Revolution" spot treatment. You can find this on the internet without prescription for about $40 for 3 treatments. Use it every 2 weeks on your pet for 3 treatments then monthly afterwards. Sprinkle "Glade" powder($1.99 per bottle) on your carpets then after one day, vacuum and do it again. Buy "Lysol all purpose cleaner" ($2.14) and pour a cup in your laundry along with detergent if you're washing a full load, if a small load then half a cup. Get "Lysol Disinfectant Spray" ($4.89) and spray your couch with a fine mist and anywhere you sleep or sit for long periods. Put a vinyl zipper cover ($5) for your mattress and get a 600 thread count sheet set for your bed ($30+). The mite cannot penetrate this thick material. If you follow this regimen for the cheyletiella mite, you will notice a drastic change right away, once you kill the mite off your pet, carpet, clothing, and furniture, over time you will eradicate this bug before it gets worse. I have used permethrin and sulfur and very strong chemicals and nothing worked, except this regimen I listed above. Good luck all!