class Oligochaeta vs nightcrawler

class Oligochaeta and nightcrawler both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Oligochaeta	Yes	No	No	No
nightcrawler	Yes	No	No	No

class Oligochaeta (noun)	nightcrawler (noun)
earthworms	terrestrial worm that burrows into and helps aerate soil; often surfaces when the ground is cool or wet; used as bait by anglers