Wilbur the pig is scared of the end of the season, because he knows that come that time, he will end up on the dinner table. He hatches a plan with Charlotte, a spider that lives in his pen, to ensure that this will never happen.
Jane (Anna Faris), a struggling but perpetually stoned actress, has a busy day ahead. She has several important tasks on her list, including buying more marijuana. Even though she already has a good start on the day's planned drug use, she eats her roommate's pot-laced cupcakes and embarks on a series of misadventures all over Los Angeles.
On behalf of "oppressed bugs everywhere," an inventive ant named Flik hires a troupe of warrior bugs to defend his bustling colony from a horde of freeloading grasshoppers led by the evil-minded Hopper.