Hello, I went through your query, there is nothing to be scared of , swallowing housefly doesn't harm you in this way. This housefly is an organic material, it goes through all the digestive process as the other foods,, after 4hrs of swallowing it, it would have 70‰digested in the body. So don't worry. Maximum you can expect diarrhoea if the housefly I'd from dirty area.