“put the cat among the pigeons”不是指“把猫放在鸽子群中”，而是（言行）造成轩然大波；招惹是非；引起麻烦。

【例句】
The principal put the cat among the pigeons when he informed the students that the excursion was cancelled.
当校长通知学生们远足取消了，这样的决定在学生中造成轩然大波。

She told all the staff they would have to cancel their holidays, and that really put the cat among the pigeons.
她告诉所有员工他们必须取消假日，这真的在员工中引起了轩然大波。