Based on the 1999 children's book of the same name. The film begins with a boy named Lucas Nickle 10 years old being tormented by a bully and his gang. In turn, Lucas attacks an anthill with a squirt gun. This terrifies the ants. One ant, an eccentric wizard named Zoc, tries to fight back. His girlfriend, a nurse ant named Hova, attempts to communicate with Lucas. She is almost crushed but is rescued by Zoc. The leaders of the colony decide to use a potion to shrink Lucas down to ant size. Lucas' parents, who fail to understand his problems, go to Puerto Vallarta, leaving him with his older sister and his Grandmother, who obsesses over aliens. Meanwhile, the local exterminator, Stan Beals, convinces Lucas to sign a contract to kill vermin. Later, Zoc and a small troop of ants pour the potion into his ear. Lucas wakes up and discovers that he is now naked and tiny. The ants agree to return him to human size if he can learn to overcome bullying.