house fly vs Musca domestica

house fly and Musca domestica both are nouns.

Word	Noun	Adjective	Verb	Adverb
house fly	Yes	No	No	No
Musca domestica	Yes	No	No	No

As nouns, house fly and Musca domestica are synonyms defined as:

house fly and Musca domestica: common fly that frequents human habitations and spreads many diseases

Other synonyms of house fly include housefly.

house fly (noun)	Musca domestica (noun)
common fly that frequents human habitations and spreads many diseases	common fly that frequents human habitations and spreads many diseases