I'm going to take a picture of the Minnesota house fly that has been alive for over six months and post it ASAP.
Houseflies pass through four distinct stages: egg, larva, pupa and adult. The life expectancy of a housefly is generally 15 to 30 days and depends upon temperature and living conditions. Flies dwelling in warm homes and laboratories develop faster and live longer than their counterparts in the wild.
The housefly's brief life cycle allows them to multiply quickly if left uncontrolled.