(at around 43 mins) In a scene where students are being called to the principal's office, one name called is Thomas Nix. In reality, Tommy Nix is one of director Robert Rodriguez's friends from college. He helped Rodriguez write his second feature Roadracers (1994).
A lot of the filming was done at the high school in Lockhart, Texas. The football team was used and the city was told to show up for the football game and were given fake t-shirts to wear in the stands.
Elijah Wood, Clea DuVall, Jordana Brewster and Shawn Hatosy appear in the music video for "Another Brick in the Wall, part 2", performed by the Class of '99, which is featured in the film's soundtrack. In keeping with her character Stokely, Clea DuVall does not lip sync the lyrics with her co-stars.
In 1990, David Wechter and Bruce Kimmel wrote their first draft of the script and sent it out, but there were no buyers. It wasn't until after the success of Scream (1996) that Miramax bought the script and rushed it into production. Bob Weinstein and Harvey Weinstein brought in Kevin Williamson to do rewrites, keeping the basic story, but rewriting the dialogue and adding new characters to make it more "hip". Originally, Williamson was set to direct the film, but he chose not to so he could direct his self-penned script Teaching Mrs. Tingle (1999). The Weinsteins brought in Robert Rodriguez to direct the film instead.
Several scenes involving an additional character named Venus, played by Kidada Jones, were shown in TV previews for the film, as well as Tommy Hilfiger commercials, but cut from the film. She is also visible in a scene in the theatrical version, standing next to Gabe (Usher Raymond) in Mr. Furlong's (Jon Stewart) science class when they are looking at the "new species" in the aquarium.
(at around 1h 9 mins) Near the end, Marybeth refuses to take the alien drug test by saying she's allergic. Jordana Brewster's character Delilah says, "Yeah, and I'm Portuguese." In real life, Brewster can speak fluent Portuguese.
(at around 10 mins) The girl student with the black top and tan skirt who laughs at Elijah Wood getting his balls smashed into a flagpole was Austin rocker Sarah Talbot, who at the time was the front woman for The Hollywood Wife Beaters. Laughing at Wood was her idea and the director kept it in.
In exchange for product placement in this film for clothier Tommy Hilfiger's fashion line, the teens from the movie's cast appeared together in a TV commercial & print ad campaign for Tommy Jeans throughout 1998.
(at around 7 mins) At the start of the movie, Coach Willis (Robert Patrick) is seen standing at the end of a long hall, then begins running down the hall in pursuit of Principal Drake (Bebe Neuwirth). The way he runs, and the way the scene is shot (cutting back and forth between Willis running and Drake trying to open the door) mirrors a similar scene in Terminator 2: Judgment Day (1991), when the T-1000--also played by Patrick--is chasing the Connors and the T-800 down a long hall while they wait for an elevator to open.
(at around 1h 30 mins) Among the motivational banners in the school's locker room is a sign that says "The will to win comes from within" which is particularly appropriate considering the body snatcher nature of the alien invaders taking over the staff and student body.
(at around 36 mins) After Christopher McDonald's character (Mr. Connor) wishes Robert Patrick's (Coach Willis) good luck with the football game, Patrick shoots at McDonald with his hand. This is an homage to McDonald's famous "Shooter" McGavin character from the film Happy Gilmore (1996).
(at around 11 mins) In the first scene where Elijah Wood's character is bullied in the washroom, it says Tito and Tarantula on the wall above his head. The next scene is Salma Hayek as the nurse, when she had previously played the character Santanico Pandemonium in the movie From Dusk Till Dawn (1996), in which she dances to the song "After Dark" which is by the group Tito & Tarantula.
Harry Jay Knowles: (at around 12 mins) the bespectacled, red-haired teacher having his injury examined by Nurse Harper (Salma Hayek). Knowles, most famous for his movie news website "Ain't it Cool News," is a long time friend of Robert Rodriguez and a fellow resident of Austin, Texas, where this movie was filmed.
The trivia items below may give away important plot points.
at around 12 mins) When Prof. Furlong (Jon Stewart) is talking to Nurse Harper (Salma Hayek), and she rebuffs him, he says, "Maybe I should just put a pen in my eye." Later in the movie, that's exactly what Zeke does.
Zeke's home appears to be the same home featured in Multiplicity (1996). If so, the cracked drive way, is an obvious nod to the opening scene in Multiplicity. Things went wrong when the wrong driveway's concrete was broken up.