House dust mites live on animal and human skin dander or hair. They prefer to find them in the dust and in beds, where they live in thousands.
It is best to change bed linen and sheets every week. Special encasing covers protect against mites. Ventilating the room three times a day for five to ten minutes each reduces the humidity in the bedroom, which is best between 45 and 55 percent. The number of plants in the room should be kept as low as possible, as they also release moisture.