carpet beetle vs carpet bug

carpet beetle and carpet bug both are nouns.

Word	Noun	Adjective	Verb	Adverb
carpet beetle	Yes	No	No	No
carpet bug	Yes	No	No	No

As nouns, carpet beetle and carpet bug are synonyms defined as:

carpet beetle and carpet bug: small beetle whose larvae are household pests feeding on woolen fabrics

carpet beetle (noun)	carpet bug (noun)
small beetle whose larvae are household pests feeding on woolen fabrics	small beetle whose larvae are household pests feeding on woolen fabrics