- “Circus bugs?! How can you be circus bugs?!”
- ―Flik, finding out that the warrior bugs aren't who he thought they were
- Main article: P.T. Flea
The ringmaster of the circus troupe, who is unwilling to give refunds after his show has lasted two minutes. His finalé consists of an act called "Flaming Death", in which he was almost incinerated. This caused him to fire his entire troupe, until a foot-long line of flies arrived outside the circus tent, wanting to see the "Flaming Death" act again. He is greedily obsessed with money, but his demeanor changes after he and his entire troupe help the ant colony defeat Hopper once and for all. His name is based on the initials of circus owner Phineas Taylor Barnum.
P.T. was voiced by John Ratzenberger, who once noted that P.T. was his favorite role.
Francis is a drag queen in the circus. Unfortunately, the effect is so convincing that insects are always mistaking him for a real girl (with the fact that his actual species being a ladybug not helping matters either). He is very short-tempered and aggressive, and it doesn't help that he's constantly being mistaken for a girl just because he's a ladybug. He is great friends with Slim and Heimlich, who try to keep him calm. He also carries Slim when the circus troupe flies.
Francis was voiced by Denis Leary.
Slim is a cinnamon brown stick insect and a clown in P.T. Flea's circus troupe. It appears that he is unhappy with his position at the circus troupe, as his boss constantly casts him as a prop instead of a character, with such castings as a broom, a pole, a stick and a splinter. He is shown to be best friends with Heimlich and Francis, and often treats other bugs with more respect in contrast to Francis' aggressive nature. However, he seems to tolerate it, as seen when he calmly broke up a fight between Francis and a couple of flies during a performance.
Unlike most stick insects, Slim does not have wings and cannot fly. Because of this, Francis usually carries him for transport.
Slim was voiced by David Hyde Pierce.
Heimlich is an obese lime caterpillar (blue as a butterfly), green stripe, blue eyes, and red antennae with dreams of becoming a butterfly. He is shown to have a gluttonous appetite and is seen eating almost all the time, especially while helping the ants construct a model bird to scare Hopper and his gang. Although brave, he still shows fear when a real bird nearly eats him. Also, when Hopper shouts at the approaching circus wagon, he frightens Heimlich who says he thinks he's going to wet himself.
Heimlich was voiced by the late Joe Ranft.
Rosie is a black widow spider with a mother-like nature. She is mostly a mother figure to the rhinoceros beetle, Dim, with whom she shares an act, and also the younger ants of the colony. She has apparently had twelve husbands who all died, making her (as she says) a "black widow widow." She sees her circus friends as her only true family.
Rosie was voiced by Bonnie Hunt.
Dim is a large blue rhinoceros beetle, with a green covered back, blue eyes, and a childlike nature, as seen when he sobs in pain after Rosie accidentally lashes one of his feet. He is also shown to be ticklish when some ant kids unintentionally tickle his thorax with their antennae while exploring beneath him. He is usually mothered by the black widow spider, Rosie. He is the largest insect of the circus troupe, and also the transport to Heimlich, Rosie, Tuck and Roll. He is big and strong but kind of cowardly like when Thud the horsefly scares his friends (although because Thud maybe was even bigger than Dim).
Dim was voiced by Brad Garrett.
Manny is a praying mantis with an English accent and the magician of P.T. Flea's circus troupe. He is very kind and courteous to his fellow circus troupe and other insects, especially the ants on Ant Island. He is also Gypsy's husband.
His act involves the "Chinese Cabinet of Metamorphosis," which is really the packaging of a Chinese Takeout. His magic act is not appreciated well by the flies in the usual audience, who insult him and throw berries at him, but the grasshoppers take it seriously, as he somehow improved.
Manny was voiced by the late Jonathan Harris.
Gypsy is a gypsy moth and Manny's wife. She is very kind as heard in most of her speaking lines. She is also very brave when she was seen luring the bird away from Heimlich and during the circus act for the grasshoppers. Furthermore, she is very defensive as shown while she was protecting her husband Manny when the grasshoppers began to get suspicious. She may be a little sensitive to gore and violence, which was shown when the ant kids made a mural of the warrior bugs defeating the grasshoppers.
Gypsy was voiced by the late Madeline Kahn.
Tuck and Roll are Hungarian twin pill bugs. They occasionally argue but are usually the best of friends. They act as cannonballs in P.T. Flea's circus troupe. They are supposed to be the main part of the "Flaming Death" act, but their arguing and fighting results in the act going totally out of control and everybody being fired. However, they don't seem to understand this and remain cheerful even at the Bug Bar. They also appear to like the sound of the phrase: "You're fired!", since they continuously repeat it throughout the film after P.T. Flea says it to them, much to Rosie's irritation.
They were both voiced by Michael McShane.
These fireflies serves as the employees of P.T. Flea's Circus. Their occupations throughout the circus include selling food in the bleachers, setups for the stage, and as living spotlights throughout the show. During an act of Manny doing his magic act, one firefly uses a lollipop to filter another firefly's light for Manny's act.
This yellow spider serves as the circus' musician playing multiple instruments using his legs. Though he plays multiple instruments, he is also seen playing the drumroll during the "Flaming Death" act and later when the ants and the Circus Bugs are about to defeat Hopper via cannon but the plan fails when rain arrives in Ant Island.
These two millipedes are P.T. Flea's use of transportation pulling two "Casey Jr. Cookies" boxes as circus wagons. P.T. uses them so that the millipedes can stop for his circus troupe can perform at certain spots.
The Circus Bugs first appear where their acts do not perform well with the flies dissatisfied of their performance with many of them leaving the circus in anger. Their leader, P.T. Flea, ruthlessly refuses to give out refunds to the flies during the first minutes of the show much to his harsh strictness to the circus troupe. When P.T. became very upset that his act did not perform properly, he decides to do a dangerous act known as "Flaming Death" to test if any of the circus troupe members survive the act in less than fifteen seconds while telling other bugs who are sensitive to the act to leave the circus immediately. P.T. survived the act after the flaming flypaper falls on him and the Circus Bugs extinguish him with water droplets, but he fires the whole troupe for bad performance in the circus.
Flik first sees them in the city at the Bug Bar after they were fired by P.T. Flea, when his "Flaming Death" act went wrong, doing a Robin Hood act, believing them to be warriors, and they believe him to be a talent scout, and he convinces them to come to Ant Island to help him deal with the grasshoppers. Shortly after arriving, Flik and the circus troupe discover their misunderstandings; Flik is horrified that he brought a circus troupe, and the circus bugs are upset that Flik didn't tell them that they were actually going to be combatting grasshoppers. As they attempt to leave, with Flik attempting to stop them, they stumble upon a bird's nest, and they, along with Dot, are attacked by the mother bird. Francis manages to save Dot from falling to her death, but they end up trapped in the riverbed. Flik and the others work together to save them both. After hearing that even Hopper fears birds, Flik proposes creating a model bird to scare him and his gang, with the circus troupe taking credit for the idea.
Later, P.T. comes to Ant Island looking for his troupe, and inadvertently reveals the truth about them. The Queen and Princess Atta banish them from the island, along with Flik as punishment for lying to the colony, however, this was a fatal mistake; they put themselves in danger. When Hopper and his gang return and take over the island, Dot eavesdrops on a couple of grasshoppers discussing Hopper's plan to squish the Queen in order to discourage opposition from the ants and follows Flik and the troupe to tell them about the dire situation. Flik is still ashamed of himself for being a screw-up all the time, but some encouragement from Dot and the troupe makes him feel better and motivated to return and stop Hopper. The circus bugs present themselves to Hopper, claiming that Princess Atta invited them as a surprise for his arrival; Hopper initially orders his gang to kill them, but after seeing Tuck and Roll fight, he decides they can use a little entertainment and spares their lives. The circus bugs continue their show until Manny takes the Queen for a magic trick, making Hopper demand to know where she is. At that moment, Flik and the blueberries launch the fake bird they constructed to scare the grasshoppers; it works, until P.T. sets it on fire and ends up aiding Hopper and his gang in the process.
After seeing Thumper beat up Flik and hearing Hopper insult the colony and his troupe, P.T. realizes his mistake and assists the ants in driving out the grasshoppers, resulting in all the grasshoppers, except Hopper, his younger brother Molt, and Thumper (until Dim and Dot scare him off), fleeing and Hopper getting killed by the real bird, putting his reign of terror and insult on the ant colony and troupe to an end. Following Hopper's defeat, P.T. reforms, becoming less greedy and more kind-hearted, and he and his troupe spend the winter on Ant Island (as it would be impossible for them to go anywhere in the rain and snow) before returning to the circus in the spring after a brief celebration, bringing Molt (now called "Tiny" and working as a strongman) and a group of acrobatic ants with them, while promising to come back in the future and receiving a fond farewell from the colony.
In the former area A Bug's Land, statues of P.T. Flea's circus troupe (excluding P.T. Flea) were added since the opening of said area. P.T. Flea's Market, a market named after P.T. Flea (originally named Santa Rosa Seed & Supply) was also a shop at the former area Bountiful Valley Farm; however, this market and the rest of Bountiful Valley Farm were closed in 2010 to make way for Cars Land.
In Pixar Pier, the Circus Bugs (including P.T. Flea and Flik) are also seen as spectators in the boardwalk game Heimlich Candy Corn Toss (re-theming of the 2009 game Casey at Bat), in addition to Heimlich being added in the game, where the player must throw candy corn at Heimlich's mouth to score points to win prizes.
- The circus bugs made a cameo appearance as circus cars at the Radiator Springs Drive-In Theatre during the end credits of Cars in which Mack complains that the characters are being voiced by the same actor (referring to Pixar actor John Ratzenberger).