House fly  (Musca domestica)

House flies contaminate food, and in developing countries are responsible for millions of infant deaths per year as a result of dehydration caused by diarrhoea (5).

House flies undergo 'complete metamorphosis'; the larvae (maggots) progress through three stages known as 'instars' before a pupal stage develops in which complex changes take place as the body of the maggot re-organises into the adult fly (4). Adults feed on rotting plant and animal matter and sugary liquids. They repeatedly salivate on food, ingest it and regurgitate it in order to pre-digest the food (4).