Flies are attracted to humans primarily because of the chemicals and substances we emit, such as carbon dioxide from our breath, body heat, sweat (which contains salt, oils, and dead skin cells), and other odors unique to each person. These substances provide nourishment and signals that attract flies, as they seek warmth, moisture, and food sources. Flies also use sensory receptors on their antennae and feet to detect these attractive chemicals and decide to land on a person. Additionally, differences in individual body chemistry, diet, genetics, and activities throughout the day can make some people more attractive to flies than others. To reduce flies being attracted to a person, one can stay clean and dry, minimize sweat, and avoid strong odors or foods that may draw flies. Using insect repellents or citronella may help, though effectiveness varies. Flies are naturally curious and persistent, which adds to why they continue to hover or land despite attempts to shoo them away. In summary, flies are attracted to humans because of the warmth, carbon dioxide, sweat, oils, and dead skin that provide both physical cues and nourishment, making people a natural target for these insects.