Book Lice
These primitive insects are often found in kitchens and bathrooms where they appear as tiny brown or opaque dots moving across work surfaces and shelving. They are usually associated with areas of high humidity and where air circulation is poor. This causes the moisture in the air to condense and microflora will form on carbohydrate based materials that become damp. This forms the food source for the book lice.
Environmental control is always the best way to control an infestation of this type. If you can dry out the atmosphere then you will destroy the Booklice, as they cannot tolerate dry conditions. Insecticide treatments can offer a very short-term control but if you do not modify the environment re-infestation will most likely occur.