Dust mites are tiny arachnids (spiders), only 1/100 of a millimetre long. Colonies of them can be living in your bedroom and family room, according to the BBC Home website. As much as one-tenth of the weight of a pillow you have used for six years may be dust mites and their fecal matter. The mites thrive in moist, humid environments; the best way to kill them is to dehydrate them. Borax powder is one of the more effective means of killing dust mites by dehydrating them.
Strip all bed linens -- blankets, sheets and pillowcases -- as well as drapes, bedspreads and valances in an infested room. Throw out old pillows and replace them with new ones.
Wash the bedding and drapes in hot water with regular washing powder and 1/2 cup of borax. Stop the washing machine when it is full of water and let it soak for 20 minutes. Then restart the washing machine and let it finish its cycle.
Sprinkle a fine layer of borax powder on carpets after removing pets and small children from the room for the day. Let the borax work on the dust mites for a few hours. It eats through their exoskeletons, dehydrating them. It can also suffocate them. Vacuum up all traces of the borax powder at the end of the day.
Wash the floors and furniture surfaces thoroughly with soap and hot water before bringing the clean linens back into the room.
Don't keep stuffed animals in the bedroom unless they are washer- and dryer-proof and can be washed periodically.
Borax is for external use only. Don't allow pets or children to eat it; don't allow it near your eyes, nose or mouth.