smell a rat懷疑；感到不對勁。這個習語取材自貓咪靠嗅覺找出藏匿的老鼠。當嗅到什麼氣味時，它們就會開始警戒，並準備行動。後來就將這個用法衍生至人的行為，比喻人如貓一般，靈敏地感覺到事情可疑、不對勁。
看看老外聊天時怎麼用smell a rat：
Gavin: The fabric supplier suddenly offered us another 15% discount.
Linda: I noticed that, too. We just received the catalogue.
Gavin: The price of those items has always been fixed.
Linda: I smell a rat. We should try to figure out what's up.
Gavin: I agree. Let's report this to Ms.in first.
加文：布料供應商突然額外給我們15%的折扣。
琳達：我也注意到了，我們剛拿到目錄。
加文：那類產品的價格通常都是固定的。
琳達：我覺得哪裡不對勁，我們應該試著去查清楚。
加文：我也這麼覺得，我們先把這件事上報給林經理吧。
smell a rat例句精選：
I don't want to say he steals them, but I really smell a rat.
雖然我不想說他偷我的書，但我確實覺得不對勁。
Why are the police looking for me? I smell a rat.
警察為什麼在找我？我覺得事有蹊蹺。
He could smell a rat in the way the men were talking.
他從這些人的講話方式就能感到事有蹊蹺。
Kelly：Dad，I saw Rick and Dan running down to the basement.
Father：Hmm..I smell a rat.I'd better go check it out.
凱莉：爸爸，我看到裡克和丹跑到地下室去了。
父親：嗯……不太對勁，我最好去看看。
拓展學習：
unusual 不平常的
sense 感覺到
perceive 注意到；領悟
proof 證據
be aware of 察覺
pull the wool over one's eyes 矇騙某人
an easy mark 易受騙者