After being shrunk down to ant size, Lucas is brought to the ant colony where he is met with hostility and fear from the ants. The queen ant orders him to be put to work as an egg carrier, but he is soon befriended by a young worker ant named Zoc and his girlfriend Hova. They teach him about the ways of the colony and how important each member is to its survival.
However, not all the ants are happy with Lucas' presence, namely the bullying soldier ant, named Fugax, who wants to get rid of him. Lucas also struggles with missing his family and dealing with the guilt of what he did to the anthill.
As he spends more time with the ants, Lucas begins to see the world from their perspective and gains a newfound respect for them. He even helps the ants defend their colony from an exterminator, using his knowledge of human technology to make traps and weapons for the ants.
By the end of the movie, Lucas has made amends with the ants and is even allowed to return to his human size. He realizes the importance of respecting all living creatures and the impact his actions can have on others.