House fly
organism to human populations; the housefly is always found in association with human activity. As the most common species of fly found on livestock farms [...] viruses (such as the Newcastle Disease virus), bacteria (such as Salmonella and E. coli ), protozoan parasites (such as Giardia ), and the eggs of many parasitic [...] parasitic worm species. Life cycle and appearance of House fly The adult house fly ( Musca domestica ) is 6–7 mm long, yellowish-grey to dark grey in colour