While stuck in an animal testing lab, rats Mike and Phil enter a love triangle with their imaginary friend, which inadvertently reveals the truth of their situation. A pair of fleas discuss their basketball dreams and ponder life, while stuck on a monkey's back. An algae questions his existence.

As a virus sweeps New York, teen pigeon Jacob's jealousy over his angelic little brother prompts a wacky spirit quest that teaches him about courage and responsibility. Two foxes rap about a hard-knock life on the city streets.

When an exterminator puts a roach town in crisis, the survivors band together to travel to the world outside of their wall and guarantee the survival of their species. A group of seagulls, stuck together by a piece of litter, struggle to live their lives as one.