There are a couple of household bugs that are either so small as to be confused for dust particles, or that actually use dust particles to camouflage themselves. Then there are the ones you cannot see due to their microscopic nature, but the presence of dust may be what alerts you to their presence.
Book lice are often found between the pages of books as the mold or mildew sometimes found there is one of their food sources. They prefer dark places that are relatively humid, and hide out in tight spots such as cracks between walls and shelving. They are tan in color, the size of a dust particle and possess soft bodies. Sometimes they also have wings. Book lice also feed on the fungi and starches present in grain products.
While these formidable warriors – at least to fellow insects – are significantly larger than a single dust particle, they have a cunning habit of using multiple dust particles to "dress" themselves. They attach the dust to their backs and lie in wait for their next meal to pass within their reach. The dust on their backs gives them the appearance of a scurrying lint ball.
That particle of dust you see may not be a bug at all, but rather dust mite excrement. Many people suffer severe allergies and asthma when exposed to dust mite waste, which is all around us. Dust mites live in damp warm places such as mattresses and pillows and feed on the dead skin cells that fall off you and your pets. Up to 10 percent of the weight of a 2-year old pillow can be dust mite excrement.
It is possible to rid your home of the first two pests, but dust mites are a fact of life. Good sanitation practice is the best way to rid your home of book lice. Use a vacuum and crevice tool to clean the pantry, sucking up any specks of spilled flour, cereals or grains. Dispose of psocid-infested open bags or boxes of food by sealing in a plastic bag and tossing in the garbage. Do the same with your vacuum bag when done. Lower the humidity in your home if possible. Professional exterminators may be called in to perform a heat treatment that kills all stages of the psocids. Assassin bugs are easily controlled by frequent vacuuming of favorite bug hiding spots, and use of a household bug spray such as is used for roaches is also effective.