People are disgusted by the sight of maggots, which are a very undesirable byproduct of insects of the order Diptera (or flies). The mere presence of maggots has a negative connotation; it connotes an unclean area that is full of disease. A single fly can carry more than one million bacteria on its body. The common house fly is a pest that most homeowners can do without, and often people do not associate the fly with the maggot. If you control flies in your home you can control the formation of maggots.
Maggots are wormlike in nature. When born they are about 5mm (2/10 of an inch) in length and they look like small grains of rice. The maggot will range from an off white to light brown in colour. At one end they have a mouth and tiny hooklike parts that help it to eat. The maggot has no legs. It will emerge from the egg after eight to 20 hours as an egg. When maggots emerge they begin feeding on the material they were laid in. Flies have four stages of development: egg, larva (maggot), pupa and adult. Once rotting flesh is found, adult flies lay eggs. The maggots then hatch and eat the rotting flesh before turning into pupa--which is similar to a cocoon stage of development--and emerging as adult flies
Flies love lots of decaying, smelling garbage. Maggots will form in anything rotten and odoriferous. All you need is an open pail of moist garbage filled with decaying food to get maggots. The ideal conditions are warm, moist areas full of decaying food that have a good odour. House flies or filth flies lay their eggs in the garbage. The maggots hatch soon after and feast their way to adul bonnet.
Faeces or manure
The warm nature of faeces or manure is the perfect home for maggot development. The odour attracts the fly, which then lays eggs in the warm faeces. The warmth of the faeces or manure acts as an incubator for the fly eggs. The warmer the stool, the faster the maggots come out. Usually hatching four to eight hours later, the maggot emerges and feasts on the faeces or manure.
Certain flies are attracted to open wounds on animals or humans. The blow fly is one such fly and the screw fly is another. The fly lands and lays eggs on the open wound. The eggs hatch and the maggots burrow into the wound. This condition is called myiasis. Some burrowing maggots will go deep into the body and lodge in certain places. They may infect the genitalia, anus, intestines, eyes, mouth, ears and sinuses of the host.
Flies have a great sense of smell and can smell death from miles away. Flies like to lay their eggs in body liquids of decaying rotten flesh. The blow fly and flesh fly will lay their eggs in the nostril of the dead animal so that the maggots will not have far to travel. As said before, the warmer the body the faster the development of the maggot; this is why bodies that turn up in cars tend to be more decomposed than most.