- To suspect that something is wrong, dishonest, deceitful, or corrupt.
- To feel that someone is being deceptive or that a situation is not what it seems.
Explanation
Origin
- Based on the literal experience that the smell of a dead or hidden rat can indicate something unseen and unpleasant is present.
- Rats themselves are often associated with disease, decay, and hidden infestation.
- Metaphorically, it means detecting hidden dishonesty or wrongdoing through subtle signs or intuition, like detecting a hidden rat by its smell.
- The expression dates back to at least the 16th century.
Synonyms & Related Expressions
Alternatives
Slang/Informal:
- Something's fishy / Smells fishy
- Seems sketchy / Looks shady
- My spidey-sense is tingling (pop culture reference to intuition of danger/wrongdoing)
- Getting bad vibes
- That ain't right
- Sounds sus (common online/younger slang, from 'suspicious')
Vulgar/Emphatic:
- Smells like bullshit / That's bullshit
- Something's fucked up / This is fucked
- Shady as fuck
Milder/Standard:
- I'm suspicious
- Something seems off / amiss
- I have my doubts
- It doesn't seem right
Situational Appropriateness
- Mostly informal to semi-formal.
- Clearly conveys suspicion or distrust.
Misunderstanding Warnings
- Entirely idiomatic. The literal meaning is irrelevant. Focus on the meaning of 'feeling suspicious' or 'detecting dishonesty'.
Examples
- The offer seemed too good to be true; I immediately smelled a rat.
- When the politician avoided answering direct questions, many journalists smelled a rat.
- He said he found the expensive watch on the street? I smell a rat.
Dialogue
Person A: My colleague called in sick today, but I saw pictures of him at the beach posted online last night.
Person B: Ooh, I smell a rat! Sounds like he wasn't really sick.
Person A: Exactly! I wonder if the boss knows.
Social Media Examples
- Tweet: Got a 'job offer' via WhatsApp asking for my bank details upfront. Definitely smell a rat! #scamalert #jobscam
- Reddit Post: The seller keeps making excuses for not shipping the item... starting to smell a rat. Should I file a dispute? #onlineshopping #ebay
- Facebook Comment: He claims he finished the project alone, but I know Amy did most of the work. I smell a rat.
Response Patterns
- Yeah, me too. Something doesn't feel right.
- Really? What makes you suspicious?
- What do you think is actually going on?
- Maybe you're just being paranoid?
- Agreement, curiosity, requests for evidence, or skepticism.
Common Follow-up Questions/Actions
After someone says they smell a rat:
- What specifically makes you suspicious?
- Do you have any proof or just a feeling?
- Who do you think is being dishonest?
- What are you going to do about it?
- Action: Becoming more cautious or vigilant.
- Action: Investigating the situation further.
- Action: Warning others.
Conversation Starter
- No.
- It's a reaction expressing suspicion about a specific situation or person's actions.
Intonation
- Stress usually on SMELL and RAT. Smell a RAT.
- Often said with a tone of suspicion, distrust, or concern.
Generation Differences
- Widely understood across generations. Might sound slightly dated to some younger people, but the meaning is generally known. Something's fishy or sketchy might be more common among younger speakers.
Regional Variations
- Common in all major English-speaking regions.