eager beaver

An eager beaver is someone who has an unbelievable amount of energy and enthusiasm — like the volunteer who shows up early because he’s so excited to start working at the tutoring center.

Use the phrase eager beaver when you’re talking about the first person to raise her hand in class or about the first volunteer to take out the trash. If you’ve ever witnessed a beaver building a dam, you have an idea of where this saying came from — beavers are unbelievably hard-working and industrious, completing impressive amounts of labor in a short time.