Perennial domestic allergies are the expression of an illness from urban civilization. The Pyroglyphidae mites, also called epithelium phages because they feed mostly on human skin scales and with bed as their ecological niches, bear the major responsibility. They may also produce sensitization to others, known as storage mites, which develop naturally in the food stores found in barn and silos as well as in badly maintained kitchen cupboards. These mites develop quickly when they find favourable atmospheric conditions (25/27 degrees C--70/75% rH) and a good source of food. To prevent their multiplication strict domestic hygiene must be combined with protection of bedding by covers and with the use of sufficient amounts of acaricides.