louse vs shaft louse

louse and shaft louse both are nouns.

Word	Noun	Adjective	Verb	Adverb
louse	Yes	No	No	No
shaft louse	Yes	No	No	No

As nouns, shaft louse is a hyponym of louse; that is, shaft louse is a word with a more specific, narrower meaning than louse:

louse: wingless insect with mouth parts adapted for biting; mostly parasitic on birds
shaft louse: a louse parasitic on poultry

Other hyponyms of louse include chicken louse, Menopon gallinae, Menopon palladum.

louse (noun)	shaft louse (noun)
wingless usually flattened bloodsucking insect parasitic on warm-blooded animals	a louse parasitic on poultry
any of several small insects especially aphids that feed by sucking the juices from plants
wingless insect with mouth parts adapted for biting; mostly parasitic on birds
a person who has a nasty or unethical character undeserving of respect