Plot Synopsis

Flik is an oddball, an individualist and would-be inventor in a colony of ants that is oppressed by a gang of marauding grasshoppers, who arrive once a season demanding food from the ants. While working with an invention to pick fruit more efficiently, Flik accidentally destroys the offering that the ants were putting together to appease the grasshoppers. Given a temporary reprieve by the grasshoppers, the ants agree to Flik's plan to recruit "warrior bugs" to fight off the grasshoppers - Flik actually believes the plan, while the other ants see it as effectively exiling Flik.

Flik finds his way to the "big city" (a garbage dump), where he mistakes a group of circus bugs, whose act collapses into chaos, for the warrior bugs he's seeking. The bugs, meanwhile, mistake Flik for a talent agent, and agree to travel with him back to Ant Island.

Flik eventually realizes his mistake and develops a new plan. He advocates building a fake bird to scare away Hopper, leader of the grasshoppers and deeply afraid of bug-eating birds. The ants unite behind Flik's plan until the circus' ringmaster arrives to retrieve the circus bugs, blowing Flik's cover.

The ants desperately try to pull together enough food for a new offering to the grasshopper, but it can't possibly be enough. Dot, a tiny royal ant, overhears Hopper's plan to kill the queen after the offering and gets her friends to put Flik's bird plan back in action. It nearly works, but again Hopper discovers he's been had. He's about to kill Flik when Flik says "you need us... and you know it, don't you?" The ants realize that, outnumbering the grasshoppers 100-to-1, they don't need to be oppressed by the grasshoppers anymore. They chase the grasshoppers out, but not before Hopper attempts his final vengeance. Thanks to some quick thinking by Flik, he ends up being eaten by the (real) bird. Flik is welcomed back to the colony, and the circus bugs join him in a celebration.