Eager beaver - Idiom of the Week
As defined in Linda and Roger Flavell’s book Dictionary of Idioms and Their Origins, an “eager beaver” is an overly excited, overly zealous person, who tries to impress people with their diligence and enthusiasm (page 110).
Wells was always known as quite the eager beaver in college. He made it his goal to always have papers and projects turned in 1-2 weeks in advance.
This idiom started in America around the beginning of the Second World War. During the war, they say this idiom was used in the armed forces to refer to those recruits that were quick to always volunteer for everything. In the 18th century, “to work like a beaver” was a popular phrase used to convey enthusiasm. Apply this to the eagerness of the keen military recruits, and you have “eager beaver” (page 110).