The film's production resulted in a controversial public feud between DreamWorks co-founder Jeffrey Katzenberg, Steve Jobs, and John Lasseter of Pixar, concerning the parallel productions of this film and Pixar's A Bug's Life. This only worsened when Disney refused to avoid competition with DreamWorks' intended first animated release, The Prince of Egypt (1998).
Antz premiered on September 19, 1998, at the Toronto International Film Festival, and was released theatrically in the United States on October 2, 1998. It grossed $171.8 million worldwide on a budget of $42–60 million. Rotten Tomatoes's consensus was that critics praised the voice cast, animation, humor and its appeal towards adults.
Z-4195, or "Z" for short, is a neurotic and pessimistic worker ant who longs to express himself. Z falls in love with the ant colony's princess, Bala, when she visits a bar to escape her suffocating royal life.
The ant colony declares war on an encroaching termite colony and a large force of soldier ants is mobilized for an attack. To see Bala again, Z exchanges places with his soldier friend Weaver and joins the army, where he befriends staff sergeant Barbatus. Z is unaware that the army's leader and Bala's fiancé General Mandible is secretly sending the soldiers loyal to the Queen Ant to die so he can stage a coup d'état. At the base of a tree near nightfall, Z realizes he is marching into battle. Everyone except Z is killed by acid-shooting termite defenders. Before dying, Barbatus tells Z to think for himself instead of following orders.
Z returns home and is hailed as a war hero. Secretly irate, Mandible congratulates him and introduces him to the Queen. There he meets Bala, who eventually recognizes him as a worker. Z panics and pretends to take Bala hostage, causing him and Bala to fall out of the anthill via a garbage chute. Z decides to search for Insectopia, a legendary insect paradise. Bala attempts to return to the colony, but quickly rejoins Z after encountering a praying mantis.
News of the incident spreads through the colony and Z's act of individuality inspires the workers and some soldier ants, halting productivity. To gain control, Mandible publicly portrays Z as a self-centered war criminal, promotes the glory of conformity, and promises them a better life through the reward of completing a "Mega Tunnel" planned by himself. However, Mandible's second-in-command Colonel Cutter becomes concerned about Mandible's plans.
After various misadventures, Z and Bala find Insectopia, a human waste bin overfilled with decaying food, where Bala begins to reciprocate Z's feelings. After interrogating Weaver, Mandible learns that Z is looking for Insectopia and sends Cutter to retrieve Bala and kill Z. That night, Cutter arrives in Insectopia and forcibly flies Bala back to the colony. Z finds them gone and returns to the colony.
When Z arrives, he encounters soldiers who forcibly direct him toward the Mega Tunnel. Along the way, he finds Bala held captive in Mandible's office. After freeing her, they both discover that Mandible's "Mega Tunnel" leads straight to the puddle next to Insectopia which Mandible will use to drown the Queen Ant and workers at the opening ceremony. Bala warns the ants at the ceremony, while Z goes to the tunnel exit to stop the workers but fails, and the water leaks in. Z and Bala unify the workers into building a towering ladder of themselves towards the surface as the water rises.
Meanwhile, Mandible and his soldiers gather at the surface, where he explains his vision of a new colony with none of the "weak elements". When the workers break through, Mandible tries to kill Z, but Cutter rebels against Mandible and instead helps Z and the worker ants. Enraged, Mandible tries to lunge at Cutter, but Z pushes Cutter out of the way and is accidentally tackled into the flooded colony with Mandible, who lands upon a root, dying on impact. Cutter orders the soldiers to help the workers and the Queen Ant up to the surface while he himself goes after Z. Although Z has seemingly drowned, Bala resuscitates him.
Z is praised for his heroism and marries Bala. Together they rebuild the colony, transforming it from a conformist military state into a community that values all of its members. The camera zooms out to reveal the whole story took place in the middle of Central Park, New York City.