louse vs chicken louse

louse and chicken louse both are nouns.

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

As nouns, chicken louse is a hyponym of louse; that is, chicken 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
chicken louse: a louse parasitic on poultry

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

louse (noun)	chicken 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