“ants in one's pants”不是“裤子里有蚂蚁”，真实含义是“紧张不安；坐立不安；魂不守舍”。

【例句】
Why do you have ants in your pants today?
你今天为什么坐立不安呢？

I have ants in my pants for the coming exam on Tuesday.
因为周二就要考试了，我坐立不安。