A lot of black spots on the back is not necessarily a sign of mites. Mites are actually a common parasite that normally exists in the human epidermis and the surrounding living environment. Most of the black spots on the back are actually open acne pimples, commonly known as blackheads, which can generally be squeezed out as a relatively hard ball of keratin, and do not require special treatment or affect health. Many people have acne on their backs because their sebaceous glands secrete more and they sweat more. Be careful not to squeeze or scratch repeatedly, as this may cause skin infections to occur. If the situation is not more serious, such as red bumps with pus and itching, it does not need to be treated separately.