Being an eager beaver, he sometimes is not well-liked by his colleagues. 

他做事非常卖力，有时不受同事的喜欢。

The boy is an eager beaver. All of us like him.

他是个勤快的小伙子，大伙儿都喜欢他。

You know that a person who works very hard is often described as an "eager beaver" or "busy beaver.

你们知道，工作非常勤奋的人常常被描绘成“卖力的河狸”或“忙碌的河狸”。

She's a real eager beaver and I'm sure she will do very well in this company.

她真是个'积极的河狸'，我敢保证她在咱们公司会很有作为的。

Mike is an eager beaver but he is not very organized.

麦克干活很勤快，但不是很有条理。