Trivia: During the spring cleaning music number, there is an older goat who pulls a rat out of a couch, wondering where it came from. At the bottom of the frame is a dead mouse in a mouse trap. It's Mickey Mouse.
Trivia: One of the parents at the school board meeting is Lin Shaye. While she had been in many movies at that point with mostly smaller parts, she would go on to be well known in two movies directed by the Farrelly brothers in the mid-1990s, Dumb and Dumber and Kingpin.
Trivia: Contrary to what it appears, the actor at the post office is not David Schwimmer despite the close resemblance. Schwimmer was active at this time, but the actor is not him.
Trivia: When Elio's clone is melting at the airforce base, he gives the real Elio a thumbs up. This is a nod to Terminator 2's ending, where a melting Arnold gives a thumbs up.
Trivia: Near the beginning of the film, the camera passes by some school buses. On the side, they say Crichton Middle School. This is a reference to the author of Jurassic Park, Michael Crichton.
Trivia: Not really a mistake - The microwave at Faraday's home is not plugged in. Since it shows up in a few shots, it's possible the filmmakers decided it would have created continuity errors if the clock was visible.
Trivia: A significant amount of the movie was shot at Hell's Half Acre, 45 minutes west of Casper, Wyoming. This substituted as the Bug planets, in particular Planet P. Some local residents of Casper were extras in the film. The crew faced difficulties with filming in Wyoming, particularly weather-related issues. At times, the area experienced high temperatures during the day, causing some actors to suffer heat strokes. At night, the temperatures would drop significantly, or it would snow.
Trivia: The Navy only authorized two actual missiles to be fired for the film. Thus a couple of the missile shots are obviously repeated, and they're easy to spot. The rest of the missile shots were done with miniatures. The company responsible for the miniatures did such a good job that an investigation was done by the Navy to see if more than two missiles had been fired.
Trivia: As was custom with a lot of films at the time, this movie makes some extensive use of rear-projection. Several scenes were shot in a studio but used filmed or still backgrounds to make it appear like they were shot on location. A lot of the scenes that take place while characters are on a horse-drawn carriage use the technique, except the shots behind the characters are moving. The biggest use of rear projection is during the horse race on the beach.
Trivia: The scene where Will Smith climbs aboard the crashed craft ("Welcome to Earth") was accomplished by using forced perspective, an in-camera technique that is as old as cinema. The ship is much closer to the camera than Will is, but it gives the illusion he is climbing aboard this massive craft. The technique is also used elsewhere in the film but this is one of the best examples.
Trivia: The film is loosely based on true events, however the real cocaine bear is not known to have attacked anyone and died as a result of the cocaine. The bear is on display in Lexington, Kentucky.
Trivia: Although the film was set in Tennessee, it was mostly shot in Ireland. The real forest seen in the movie is in northern Georgia in the Blue Ridge Mountains.
Trivia: When Jeff tries to get Red to pull over on the road, he almost misses an RV and has to swerve at the last minute. In front of where he swerves is a big rock looking thing, right frame. It is there to hide the camera filming the lower angle shot we see in this sequence.
Trivia: For the film, a real radio tower was built, albeit significantly shorter. The film was shot on a tall mountain, to give the illusion that the tower was much taller. A blue screen was placed below it. The two main female characters did their own stunts.