The Antius Maximus was a giant ant farm built by Phineas and Ferb to know how to live in an ant society. The song plays when they are inside. ("Gi-Ants").
Inspiration[]
When Phineas and Ferb sees Candace's Baklava teddy bear got infested with ants, they get curious about life is like in an ant society.
Design and Construction[]
They first build a scale model to introduce their friends, and later introduce the real model. The model was a giant ant farm that has an ant resize-izers that makes the ants grow larger and follows the light to the Antius Maximus. Before they entered, they need to get sprayed with ant pheromones to co-exist with the ants but warns not too much to get too much attraction.
Known Guests[]
Aftermath[]

Giant ants evolved into enlightenment
Candace becomes the ant queen due to being sprayed with too much ant pheromones. She asks for a salad and a queen dress, causing the ants to evolve into an agricultural society, and soon after have an Industrial Revolution. She also ordered the ants to develop cell service, causing the ants to enter the information stage. This caused them to have advanced intelligence and declared independence from Candace, forming a democratic government. The Ants later entered into the stage of "enlightenment" are able to speak and gain telekinesis. They leave Earth to look a place for themselves in space.
The Antius Maximus itself is hit by Doofenshmirtz's Turkey-Inator, causing it to transform into a giant turkey. The evolved ants takes it as a snack for their journey.
The Antius Maximus apparently took place on the same day as Phineas and Ferb tried to stop a Whalemingo planet from destroying the Earth, and Candace could not try to bust them again because of signing a "Bust Accord" with Linda to not try to bust her brothers more than once a day. Midnight marks the start of a new day, allowing her to try again.