The “Rat Pack” will forever be associated with Las Vegas.

We decided to learn more about this merry band of miscreants, and quickly realized there’s a lot we didn’t know. Some of these Rat Pack facts might surprise you, too.

1. Originally, the Rat Pack was a group of friends centered around the group’s leader, Humphrey Bogart. The original members included Errol Flynn, Nat King Cole, Mickey Rooney, Jerry Lewis and Cesar Romero.

2. Nobody’s sure where the “Rat Pack” name came from, but most attribute it to Lauren Bacall. Bogart and Bacall lived in a neighborhood called Holmby Hills, so their house and the original group were sometimes called the Holmby Hills Rat Pack.

3. The original rat pack had a coat of arms, a rat gnawing on a human hand. The group’s motto was “Never rat on a rat.”

4. Later, the name was used for a variation of the group with Frank Sinatra, Dean Martin, Sammy Davis Jr., Peter Lawford and Joey Bishop. The group didn’t call itself the Rat Pack, though. They used “The Summit” or “The Clan.”

5. The Rat Pack had several “associate” members, called “Rat Pack Mascots,” including Marilyn Monroe, Angie Dickinson, Shirley MacLaine, Lauren Bacall, Juliet Prowse and Judy Garland.

6. The Copa Room at the Sands was considered the “home” of the Rat Pack. The Sands was opened in 1952 and was imploded in 1996. The Venetian now stands on the former site of the Sands.

7. In Las Vegas, when a member of the Rat Pack would be scheduled for a performance, the rest of the Rat Pack would turn up for an impromptu show. The multi-talented performers sold out almost all of their appearances, and visitors would stream into Las Vegas, often sleeping in their cars if they couldn’t find rooms. Hotel-casino marquees were known to tease the Rat Pack’s appearances. For example, the Sands marquee read: “Dean Martin, Maybe Frank, Maybe Sammy.”

8. Peter Lawford was John F. Kennedy’s brother-in-law. Kennedy would sometimes hang out with the Rat Pack in Vegas, and when they did, they referred to themselves as the “Jack Pack.” A falling out between Sinatra and the Kennedys about Sinatra’s links to the mob got Peter Lawford booted from the group.

9. Frank Sinatra once ordered 300 Bloody Marys from room service for a Rat Pack party.

10. Dean Martin’s son, Dean Paul Martin, died in a plane crash in 1987 on the San Gorgonio Mountain in California. Frank Sinatra’s mother, Dolly, was killed in a plane crash 10 years earlier on the exact same mountain.

11. Among the Rat Pack, Sammy Davis Jr.’s nickname was “Smokey.” While not commonly known, he was an accomplished quick-draw artist. When Davis was denied entry into the Copacabana, Sinatra used his clout to ensure he got in the next time. When Davis wasn’t allowed to stay in the Las Vegas hotel where he was performing, Sinatra helped Davis sidestep the racist practices so prevalent in Las Vegas at the time.

12. Rat Pack member Dean Martin would often deal blackjack at Las Vegas casinos.

13. The first movie all five Rat Pack members appeared in together was “Ocean’s Eleven.” It was released in 1960. Frank Sinatra played Danny Ocean.

14. The Rat Pack recorded five live albums together, including “The Rat Pack Live at the Sands” in 1960.

15. The last time Sinatra, Martin and Davis would appear in a movie together was “Cannonball Run II.”

Now you know! Have any fun Rat Pack trivia? We’d love to hear it.