Nouns

(n)louse, sucking lousewingless usually flattened bloodsucking insect parasitic on warm-blooded animals
(n)worm, louse, insect, dirt balla person who has a nasty or unethical character undeserving of respect
(n)plant louse, louseany of several small insects especially aphids that feed by sucking the juices from plants
(n)bird louse, biting louse, lousewingless insect with mouth parts adapted for biting; mostly parasitic on birds