The title did not come from the script, the director or the studio. In one scene, actor David Arquette improvised the phrase "Eight Legged Freaks" and that became the title. The original title was "Arac Attack" (in many European countries the film was released under that title). The scene can be seen in the movie with the phrase intact.
Eight Legged Freaks when Chris & Harlan are attempting to contact outside agencies by cell phone from the top of the communication dish, Chris advises the operator what the issue is when the operator answers that they believe it is a prank call Chris yells down the phone "They're here! They're here!" this would appear to be an obvious reference to Invasion of the Body Snatchers (1956) this is screamed by Kevin McCarthy at passing traffic at the end of the film,.
When the town's people have fled into the mall, the mayor, Wade, asks the goofy sheriff's assistant Pete what the hell just attacked him. Pete answers: "A spider, man", swallowing the syllable 'a', making it an obvious reference to Spider-Man, Marvel's comic book superhero. 14 years later, Scarlett Johansson would eventually star in Captain America: Civil War (2016) which features Spider-Man as among the superheroes.
A sequel was originally announced by producer Dean Devlin back in 2003, it would of had Ellory Elkayem returning to direct and David Arquette re-praising his role as Chris McCormick. Nothing more was ever said about it, and the sequel got scraped for reasons unknown.
When the mayor sees all the people running towards the mall, he says the line: "If you build it, they will come!". It's inspired by the line : "If you build it, he will come." from Field of Dreams (1989) starring Kevin Costner.
During the car ride to the mall, Harlan is convinced the spiders are aliens. Chris responds "They are spiders are from Mars." David Bowie came out with 'The Rise and Fall of Ziggy Stardust and The Spiders from Mars' in 1972 and the spiders from Mars are referenced in the song 'Ziggy Stardust.'
Scarlett Johansson, Scott Terra and Kari Wuhrer have all been attached to Marvel projects. Terra played a young Matt Murdock in Daredevil (2003), Wuhrer has voiced the character of Shield Agent Maria Hill in multiple Marvel animations, and most notably Johansson has portrayed Natasha 'Black Widow' Romanov in the MCU franchise.
A Springfield M1903A3 is one of the rifles that Deputy Pete Willis (Rick Overton) takes from the gun locker at the station. For some reason, he says that this weapon is the "Lee Harvey Oswald rifle", which was actually a Carcano M91/38. Later Harlan Griffith (Doug E. Doug) also refers to it as the Lee Harvey Oswald rifle. The rifle is then mainly used by Norman the maintenance guy.