This blog comes from the bottom of my bin. The bin men emptied the contents of two weeks worth of rancid and rotting remnants; the decay accelerated by a few rare days of high temperatures. Wriggling around at the bottom amongst some sticky waste and the remnants of goodness knows what lay a dozen or so maggots.
Maggots hatch from 8-24 hours according to the temperature and feed on the organic matter in which it finds itself. In temperatures of 25°C a house fly can complete the lifecycle in 16 days, less if the temperatures are higher. In laboratory conditions flies can hatch from an egg and fly off within a week.
Flies don’t look after their eggs but will choose to lay their eggs where they will have plenty to eat when they hatch. Flies can lay 100-150 eggs at a time in organic waste, faeces or exposed foods. Or flies may creep into your kitchen bin and deposit eggs on the sly.
In hot weather the core temperature of the bin is high and could become a breeding ground so make sure you keep the lid closed at all times. Flies are attracted to strong smells so hose and disinfect after the bin is emptied. Line the bin with newspaper to soak up any pungent juices and dispose of it regularly.
Experiments in which flies have been allowed to walk over culture media in sterile dishes have resulted in the growth of over 100 bacterial and fungal colonies from bacteria and fungal spores which the fly deposited so if you see a fly swot it!