In 1988, Walt Disney Feature Animation was pitched a film called Army Ants, about a pacifist worker ant teaching lessons of independent thinking to his militaristic colony. Years later, Jeffrey Katzenberg, then chairman of Disney's film division, had left the company in a feud with CEO Michael Eisner over the vacant president position after the death of Frank Wells. Katzenberg would later go on to help co-found DreamWorks with Steven Spielberg and David Geffen, and the three planned to rival Disney with the company's new animation division. Katzenberg at DreamWorks began developing projects he tried to pursue or suggested while at Disney, including The Prince of Egypt, a collaboration with Aardman Animations which resulted in Chicken Run, Sinbad, and Army Ants. Also many ideas for the film were borrowed from a scrapped PDI film pitch for a computer-animated film from 1991 called Bugs: Lights Out about microscopic robots that take apart machinery.
Production began in May 1996, after production had already commenced on The Prince of Egypt. DreamWorks had contracted Pacific Data Images (PDI) in Palo Alto, California to begin working on computer-animated films to rival Pixar's features. Woody Allen was cast in the lead role of Z, and much of Allen's trademark humor is present within the film. Allen himself made some uncredited rewrites to the script, to make the dialogue better fit his style of comedic timing. An altered line from one of his early directed films, Everything You Always Wanted to Know About Sex* (*But Were Afraid to Ask) was included – "I was going to include you in my most erotic fantasies..."
After DreamWorks' acquisition of PDI, Pixar director John Lasseter, Steve Jobs, and others at Pixar were dismayed to learn from the trade papers that PDI's first project at DreamWorks would be another ant film, to be called Antz. By this time, Pixar's project, then similarly called Bugs, was well known within the animation community. In general, both Antz and A Bug's Life center on a young male ant, a drone with oddball tendencies, who struggles to win a princess's hand by saving their society. Lasseter and Jobs believed that the idea was stolen by Katzenberg. Katzenberg had stayed in touch with Lasseter after the acrimonious Disney split, often calling to check up. In October 1995, when Lasseter was overseeing postproduction work on Toy Story at the Universal Studios lot, where DreamWorks was also located, Lasseter and Andrew Stanton visited Katzenberg and they discussed their plans for Bugs in detail. Lasseter had high hopes for Toy Story, and he was telling friends throughout the tight-knit computer-animation business to get cracking on their own films. "If this hits, it's going to be like space movies after Star Wars" for computer-animation studios, he told various friends. "I should have been wary," Lasseter later recalled. "Jeffrey kept asking questions about when it would be released."
When the trades indicated production on Antz, Lasseter, feeling betrayed, called Katzenberg and asked him bluntly if it were true, Katzenberg confirming it. Katzenberg recalled Antz came from a 1991 story pitch by Tim Johnson that was related to Katzenberg in October 1994. Another source gives Nina Jacobson, one of Katzenberg's executives, as the person responsible for the Antz pitch. Lasseter refused to believe Katzenberg's story. Lasseter recalled that Katzenberg was under the impression that Disney was "out to get him" and that he realized that he was just cannon fodder in Katzenberg's fight with Disney. Eisner had decided not to pay Katzenberg his contract-required bonus, convincing Disney's board not to give him anything. Lasseter grimly relayed the news of Antz to Pixar employees but kept morale high. Privately, Lasseter told other executives that he and Stanton felt terribly let down.
At the time, the current Disney studio executives were starting a bitter competitive rivalry with Jeffrey Katzenberg and his new DreamWorks films. In 1995, Katzenberg announced The Prince of Egypt to debut in November 1998 as DreamWorks' first animated release. A year later, Disney scheduled Bugs to open on the same weekend, which infuriated Katzenberg. Katzenberg invited Disney executives to DreamWorks to negotiate a release date change for Bugs, but the company refused to budge. DreamWorks pushed Prince of Egypt to the Christmas season and the studio had decided not to begin full marketing for Antz until after Prince of Egypt was released. Disney afterward announced release dates for films that were going to compete with The Prince of Egypt, and both studios had to compete with Paramount Pictures, which was releasing The Rugrats Movie in November, based on Nickelodeon's animated series Rugrats. Katzenberg suddenly moved the opening of Antz from March 1999 to October 1998, in order to successfully beat A Bug's Life into cinemas.
David Price writes in his 2008 book The Pixar Touch that a rumor, "never confirmed", was that Katzenberg had given PDI "rich financial incentives to induce them to whatever it would take to have Antz ready first, despite Pixar's head start". Jobs furiously called Katzenberg to explain that there was nothing he could do to convince Disney to change the date. Katzenberg said to him that Jobs himself had taught him how to conduct similar business long ago, explaining that Jobs had come to Pixar's rescue from near bankruptcy by making the deal for Toy Story with Disney. He flat-out told Jobs that he had enough power with Disney to convince them to change specific plans on their films. Lasseter also claimed Katzenberg had phoned him with a final proposition to delay Antz if Disney and Pixar changed the date of A Bug's Life, but Katzenberg vehemently denied this. Jobs believed it was "a blatant extortion attempt".
As the release dates for both films approached, Disney executives concluded that Pixar should keep quiet on Antz and the feud concerning DreamWorks. Regardless, Lasseter publicly dismissed Antz as a "schlock version" of A Bug's Life; however, Lasseter later admitted that he never saw the film. Lasseter claimed that if DreamWorks and PDI had made the film about anything other than insects, he would have closed Pixar for the day so the entire company could go see it. Jobs and Katzenberg would not back down and the rivaling ant films provoked a press frenzy. "The bad guys rarely win," Jobs told the Los Angeles Times. In response, DreamWorks' head of marketing Terry Press suggested, "Steve Jobs should take a pill." Tensions would remain high between Jobs and Katzenberg for many years after the release of both films. According to Jobs, years later, Katzenberg approached him after the opening of Shrek, and insisted that he had never heard the pitch for A Bug's Life, reasoning that his settlement with Disney would have given him a share of the profits if that were so. In the end, Pixar and PDI employees kept up the old friendships that had arisen from working in computer animation for years before feature films.
The final product of both films are generally perceived to contrast one another in tone and certain plot points. Antz in the end seemed to be more geared towards older audiences, featuring moderate violence, mild sexual innuendoes, and profanity, as well as social and political satire. A Bug's Life was more family-friendly and lighthearted in tone and story. The two films especially differ in their artistic look: Antz played off more realistic aspects of ants and how they relate to other bugs, like termites and wasps, while A Bug's Life offered a more fanciful look at insects to better suit its story. PopMatters journalist J.C. Maçek III compared the two films and wrote, "The feud deepened with both teams making accusations and excuses and a release date war ensued. While Antz beat A Bug's Life to the big screen by two months, the latter film significantly out grossed its predecessor. Rip off or not, Antz's critical response has proven to be almost exactly as positive as what A Bug's Life has enjoyed."