Lucas is a tiny toddler, who is bullied by one of the kids who is bigger in size. In turn, to take out his frustration, Lucas bullies ants. He destroys their nests, floods their nests and kills the ants. He is named Peanut, the Destroyer. Peanut is what his mother calls him. 

Zak, the ant wizard, prepares a magic potion. The potion reduces Lucas' size to that of a baby ant. The ants kidnap him and take him along. In a congregation the queen ant decides to give Lucas a unique punishment. She orders that he can leave their nest when he becomes an ant himself.

The rest of the movie is about how Lucas, helped by Olga (Zak's girlfriend) learns the virtues of teamwork and hard work that ants swear by.