The FT Squad, with Donkey as their new recruit, shrink down in size and meet a colony of ants that is threatened by a greedy group of grasshoppers. The grasshopper leader, Hopper, who Roark Stork is working for, threatens the ant colony into giving them food before each winter. The squad sees this as slavery and does not tolerate it. One ant from the colony, Flik, also doesn't accept it. Together, they travel to the Bug City in search of help. They find a troop of bugs who they think are warriors, but to their horror, they later realize they are a bunch of clowns from an unpopular circus.
- Lord Roark Stork guest stars in this movie. Since the ants fear birds, Roark, being a bird himself, threatens to eat the ants if they don't give the grasshoppers the food they demand.
- Because of their dislike of birds, the ants hold a big grudge against Cassidy, and to a similar extent, Elsa, because Cassidy is a pelican, and Elsa, while not a bird, looks like one, even though she is a pterodactyl.
- Dennis the Frog develops a big dislike of Hopper because during his Future Time Travel training, he had the nickname "Hopper" while learning gymnastics.
- The FT Squad, while looking like a perfect match against the grasshoppers, isn't fully trusted by the ant colony, so the colony shows no hesitation in letting them go with Flik in his search for help. Later on in the movie, they start trusting them and make them feel right at home during their stay.