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. Two fleas discuss their basketball dreams and ponder life. An algae questions its 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 their wall and guarantee the survival of their species. Stuck together by a piece of litter, a group of seagulls struggles to live as one.

With New York City quarantined and in disarray, squirrels Mike and Phil prepare for their mother's remarriage. As Mike tries to impress a female guest, Phil plots to stop the wedding, squaring off with his soon-to-be little brother, the attention-hog Mason.

Inside the headquarters of evil conglomerate Pesci Co., the unscrupulous Dr. Labcoat prepares for the roll out of the "Green Pill," a mysterious cure for the virus plaguing New York City.

Rat teens Mike and Phil plot to exploit a human baby for profit, but things take a dark turn as the stakes increase. Two bees fight over the love of a tulip.

As rival alley-cat crews face off for control of the streets of Little Italy, a young feline, Phil, rises to the top of the pack. Elsewhere, a trio of owls gather for Christmas celebrations.

In the conclusion of the war for power among New York's cat gangs, Phil runs the show while Mike looks for a way out, leading to a dramatic showdown between pussies.

In an interconnected exploration of the urban food chain, two ends of a worm search for love and independence, a pair of newly hatched bluebirds fight for survival, and an opossum father and son butt heads over the reality of being predators.

An old dog reflects on her life and doles out sage advice. As high school graduation approaches, rat teens Phil and Mike consider what comes next as their paths appear to be going separate ways.