Flies are unique in that they undergo a complete metamorphosis at each transitional stage of their lives. From fly eggs to larvae, then pupae to full grown adults, each stage is completely different from the previous and next. Perhaps most disturbing are the fly larvae, more commonly known as maggots. These larvae hatch from the eggs, sometimes in as little as 24 hours.

The maggots then feed for a few days – with the length of time depending on the species – and are soon ready to enter the pupal development stage. From there, they will soon enter the adult stage, where they’ll turn into the buzzing nuisance you and your fly swatter are most familiar with.

Flies lay eggs in different sizes, shapes and locations, depending on the species. The common house fly lays eggs that resemble grains of white rice. Within 24 hours of being laid, maggots emerge from the eggs. These maggots – or fly larvae – look like tiny, pale white worms.

Maggots do best in an environment of decay. Rotting animal or plant matter suit the larvae, especially if there is an element of fecal matter in the mix. Dead animal corpses make an excellent environment for larvae, which is why you’ll often see maggots ÔÇčemerge” from a dead animal.

Even though maggots are a prime source of food for creatures such as reptiles and birds, there are enough of them to survive predators, which is why there will always be flies around to bother you.

With house flies, the larvae take approximately five days to store up enough energy for the pupal development stage. When they’ve had enough food, the larvae seek out dark, dry locations. During this stage, the maggots develop dark shells over their soft, white bodies. This helps to protect them from predators as they prepare for their final metamorphosis.

Soon, the adult fly emerges from the pupa case. Within just a few hours, the adult fly is ready to breed. This short amount of time, from birth to adult, is what can sometimes make fly infestations so sudden and troublesome..