Demodex folliculorum is a microscopic mite that lives in the hair follicles of humans, particularly on the face. These tiny creatures are usually harmless and feed on dead skin cells and oils produced by the skin. They are most commonly found in areas with a high concentration of sebaceous glands, such as the cheeks, forehead, and nose. While Demodex folliculorum is a normal part of the skin's microbiome, an overpopulation can lead to skin issues like rosacea or acne. Factors such as hormonal changes, stress, and a weakened immune system can contribute to their increase. Regular skin care can help maintain a healthy balance of these mites.