When a fly is born, it will pass through all four stages of its life cycle fairly quickly. According to the World Health Organization, the entire life cycle takes between six and 42 days. An egg develops into a larva that is inactive for a couple of days before hatching into a pupa. The pupa is inactive for three to six days before it develops wings and legs. After emerging, it will deflate its pupa case. Then it will fly into the air and reproduce within a couple of days.
Baby flies develop into adults in seven to ten days. Their larval stage is a small, white worm-like stage. During this stage, they develop the characteristics of adults. They emerge from their pupal casing and begin looking for a mate. The entire process of maggot development takes approximately seven to ten days.
Adult flies can live up to two months. During this stage, they can survive without food for two to three days. The right food and environment can increase their lifespan significantly. Furthermore, adult flies tend to live longer in cooler temperatures. Moreover, a suitable diet can extend their lifespan by as much as 15 days. Adult flies are also required to eat before they can copulate. Female flies need protein in order to mate. Manure alone is insufficient.
House flies are the most common flies in homes. These flies are one-quarter of an inch long and live for about 15 to 25 days as adults. During this time, they undergo several changes. They may become a different color, shape, or size.