Common house flies can be 6-8mm long with a grey thorax and 4 longitudinal stripes along this. Eggs can be laid on any vegetable or animal matter providing it is not too dry and can hatch anywhere between 8 hours to 3 days. The fly larva is white and legless turning to a waxy ivory yellow in colour and more commonly known as the maggot. Pupation follows, usually taking place in the soil and this period will vary from 3 to 28 days depending on the temperature. Adult flies can exist in broods from June but are more numerous in August and September.
House flies can transmit diseases when feeding on liquefiable solid food, which may be moist, purifying material or food stored for human consumption. Flies liquefy food by regurgitating digestive juices and their stomach contents onto the food substance. However, flies may also carry disease on their bodies and transfer these when in contact with other surfaces.