Ever heard someone say they got “ratted out”? It’s a phrase that pops up in all sorts of situations. “Rat someone out” means you tell on someone—usually by revealing a secret or exposing something they hoped to keep quiet. People use it when someone informs an authority figure about a wrongdoing or breaks trust by snitching.
The phrase probably comes from the idea that rats are sneaky and betray their own kind by running off or revealing secrets. Over time, folks started calling someone a “rat” or saying they “ratted someone out” to describe this kind of betrayal.
That’s why the phrase feels so negative—it’s all about snitching or tattling, and nobody wants to be that person.
Historical Origins of ‘Rat Someone Out’
“Rat someone out” has roots in the old image of rats as sneaky, untrustworthy animals. People started using it to describe those who betray or inform on others, especially in criminal or secretive situations.
If you look at how the word “rat” changed over time, you’ll see why we use this phrase today.
Development of the Term ‘Rat’ as an Insult
People began using “rat” as an insult in the early 1600s. It described someone who deserted others, kind of like how real rats would flee a sinking ship or burning house.
Rats ran from danger fast, so folks started calling someone a “rat” if they couldn’t be trusted and would turn their back when things got rough.
This idea made “rat” a symbol of betrayal and cowardice. It wasn’t just about animals anymore—if you called someone a rat, you accused them of being a turncoat or double-crosser.
First Recorded Uses in Literature and Slang
Writers in the 1600s used “rat” to describe people who abandoned others or acted deceitfully. Even by the 1500s, people would say “to smell a rat” when they suspected something fishy or dishonest.
In the 18th and 19th centuries, phrases like “to rat on someone” started showing up. That meant betraying someone, especially by telling authorities about their wrongdoing.
“Rat” also became prison slang back then, describing criminals who gave information to guards or police.
Transition to Meaning ‘Informer’ or ‘Betrayer’
By the 19th century, people used “rat” to mean someone who informs on others. This was especially true in criminal circles or gangs, where telling the police about your accomplices was the ultimate betrayal.
During American Prohibition, “rats” also meant people who carried illegal liquor or betrayed smugglers. Over time, “rat” stuck as a word for anyone untrustworthy, especially if they “ratted out” a friend by spilling secrets to outsiders.
Curious about the details? You can check out more about the origins of rat as an insult and informer in this idiom rat history and the prison term “ratted out”.
Related Slang and Cultural Impact
Calling someone a rat isn’t just about “ratting someone out.” It connects to a bunch of words and images about snitches, criminals, and people you just can’t trust.
These terms shape how you see informants in stories, police work, and even everyday conversation.
Stool Pigeon, Stoolie, and Other Informant Terms
You might have heard the words stool pigeon or stoolie when talking about snitches. They came from old gambling slang.
Originally, a stool pigeon was a real pigeon tied to a stool to lure other birds—just like a person might get used to trap criminals. By the 1840s, stool pigeon meant someone who gave info to police or bosses.
Stoolie is just a shorter, modern take, often used by police or in crime stories. Sometimes you’ll hear canary, which used to mean a singer but became slang for someone who “sings” to the police.
There are a lot of names for informants, especially in crime or law enforcement.
The Reputation of Rats in Language and Pop Culture
Calling someone a rat is more than just an insult. It means you see them as cheap, unpleasant, or disloyal.
Rats got this bad reputation because people linked them to fleeing, spying, and sneaking around. In pop culture, rats often stand for people who snitch or betray others.
You’ll notice this in movies where a gang member called a “rat” is the one who talks to police. The reputation goes way back, when rats were seen as symbols for drunkards, lazy folks, or even cheaters.
That negative image sticks with you whenever you hear the term, making it a strong word to accuse someone of betraying their own group.
Modern Usage in Law Enforcement and Crime
Police still use rat and stoolie when talking about informants. If someone in a criminal group talks to cops, people usually call them a rat.
Law enforcement uses these words to warn others about possible informers. Internal Affairs officers might get called rats by fellow police who don’t like being watched.
In criminal circles, being labeled a rat can lead to real trouble since it shows someone broke a code of silence.
When you understand the slang, you see how trust and betrayal really shape both crime and police work.
Regional Variations and Similar Expressions
People use similar phrases in lots of places and languages. In Spanish, for example, folks might call a selfish or stingy person a rata, which literally means rat.
If someone says “hacerse la rata”, they’re talking about skipping school or dodging responsibility. That’s a pretty common way to call someone out.
In American unions—especially in the old printing trades—members called a person who refused to join a strike a rat. They wanted a word for someone who wouldn’t back up the group.
Other cultures have their own take on rats. In Hinduism, people connect the rat to the god Ganesha, and actually treat it as sacred.
But if you call someone a rat for telling on others or betraying trust? That’s always a heavy insult, at least around here.
All these variations show how the meaning of rat shifts, but it never really loses its tie to trust and betrayal.
If you’re curious, there’s a deeper dive into why “rat” became slang for snitches in this Slate Magazine article.
