The senior employee acted like a sheepdog for the young team members, making sure they didn't make mistakes.

sheepdog 是复合名词，由 sheep（羊）和 dog（狗）组成。 sheep 指"绵羊"，dog 指"狗"，sheepdog 字面意思是"牧羊犬"，用来守护和引导羊群的狗。 在句中用作比喻，形容老员工像牧羊犬守护羊群一样，细心照看和指导年轻团队成员。