(as) busy as a beaver (building a new dam)

Very busy, assiduous, or hardworking. The phrase refers to beavers' reputation for being extremely industrious. Between working two part-time jobs, volunteering on the weekends, and looking after his little brother, Sam's been busy as a beaver this summer. I've been as busy as a beaver building a new dam this year. I've had almost no free time! Believe me, this audit has kept everyone in the department busy as a beaver for months. We can't wait till it's over!

*busy as a beaver (building a new dam)

and *busy as a bee; *busy as a one-armed paperhanger; *busy as Grand Central Station; *busy as a cat on a hot tin roof; *busy as a fish peddler in Lent; *busy as a cranberry merchant (at Thanksgiving); *busy as popcorn on a skillet

very busy. (*Also: as ~.) My boss keeps me as busy as a one-armed paperhanger. I don't have time to talk to you. I'm as busy as a beaver. When the tourist season starts, this store is busy as Grand Central Station. Sorry I can't go to lunch with you. I'm as busy as a beaver building a new dam. Prying into other folks' business kept him busy as popcorn on a skillet.

busy as a beaver

Also, busy as a bee. Hardworking, very industrious, as in With all her activities, Sue is always busy as a bee, or Bob's busy as a beaver trying to finish painting before it rains. The comparison to beavers dates from the late 1700s, the variant from the late 1300s. Also see eager beaver; work like a beaver.

busy as a beaver/bee

Extremely industrious. The proverbial comparison to bees dates from Chaucer’s time. The one to beavers is newer, going back only to the seventeenth century; it also is put as works like a beaver and eager beaver. Among more recent proverbial comparisons for being busy, which liken it more to nervous overactivity than ambitiousness, is busy as a one-armed paperhanger, an Americanism dating from about 1910.