Norway rat vs brown rat

Norway rat and brown rat both are nouns.

Word	Noun	Adjective	Verb	Adverb
Norway rat	Yes	No	No	No
brown rat	Yes	No	No	No

As nouns, Norway rat and brown rat are synonyms defined as:

Other synonyms of Norway rat include Rattus norvegicus.

Norway rat (noun)	brown rat (noun)
common domestic rat; serious pest worldwide	common domestic rat; serious pest worldwide