Musca may refer to two distinct subjects in science: a genus of flies and a southern constellation. Musca (genus) is a genus of flies in the family Muscidae. The most familiar species is Musca domestica, the common housefly, but the genus includes many related species that breed in decaying organic matter. Members are generally small to medium-sized, with a single pair of wings and prominent eyes. The life cycle consists of egg, larva (maggot), pupa, and adult, typically completing in a few weeks under warm conditions. Ecology and behavior vary among species, but adults commonly feed on liquids and various foods, while larvae develop in manure, decaying vegetation, or other organic substrates. Musca flies are widespread in urban and rural habitats. They can act as mechanical vectors for pathogens, though their role in disease transmission is often secondary to more specialized vectors. They are also used in forensic entomology to help estimate postmortem intervals in investigations. Control measures focus on sanitation to reduce breeding sites, proper waste management, and, when needed, traps or insecticides. Musca (constellation) is a small constellation in the southern sky. Its name is Latin for “the fly.” It was introduced by Nicolas Louis de Lacaille in 1752. The constellation lies in a region with relatively faint stars and is bordered by other southern constellations such as Carina, Circinus, and Chamaeleon. The Milky Way runs through the area, yielding numerous star fields and faint deep-sky objects. The brightest stars are modest in magnitude, so the pattern is best seen from southern latitudes during the Austral winter months. The name reflects historical astronomical naming practices rather than a distinct astronomical feature.