Dust mites: All homes, offices and other dwellings are endowed with dust mites (Dermatophagoides pteronyssinus and Dermatophagoides farinae). These miniscule mites neither bite nor infest people or other animals. Instead, they feed upon shed skin flakes and other organic detritus that accumulate on floors and furniture. People may develop an allergic sensitivity to fragments and exudates of the mites, and this is a good reason to try to reduce the populations of these mites in the home. This is most reasonably accomplished by frequent removal of dust and debris with moist mops and cloths.
Clover mites: Each springtime and through the summer, tiny red-colored mites are seen rapidly scurrying on walls and rocks outdoors, and occasionally inside of homes. The discovery of red-colored mites in the home causes many people to mistaken these to be bed bugs, biting mites or other undesirable creatures. Often, these are clover mites (Bryobia praetiosa), incredibly common and abundant plant-feeding mites. They neither bite nor infest people or other animals. The main problem that results from these mites may be the red stains that result when the mites are crushed.
Clover mite - Bryobia praetiosa