- “Hey, cutie! Wanna pollinate with a real bug?”
- ―One of the Fly Brothers, thinking Francis is a girl
In the film, while sitting in the audience at P.T. Flea's Circus and heckling the performance, the Fly Brothers mistakenly flirt with Francis, believing him to be a girl. Annoyed by this, Francis picks a fight with them, saying that "judging by (their) breath, (they) must (had) been buzzin' around a dung heap all day!".
The Fly Brothers and the other flies enjoy P.T.'s Flaming Death act, especially when it goes completely wrong and P.T. is set alight (even one fly shouting, "Burn 'im again!").
The flies later find Francis and the other fired Circus Bugs at the Bug Bar in the city looking for payback, and they bring an over-sized horsefly friend named Thud along with them. Francis tries to get rid of them by playing a Robin Hood act with Francis (as Robin Hood), Slim (as a sword) and Heimlich (as Little John), but they don't fall for it. Thud threatens Slim and scares the bugs, including Dim (because Thud was maybe even bigger than him). Dim's weight causes the barrel to roll. However, Flik, who was in the bar looking for warriors, sees this as a sign that they are real and invites them to go to Ant Island (but didn't see the whole incident because he was forced outside by the crowd).
The Fly Brothers and Thud were last seen waking up after being unconscious and wondering where the Circus Bugs went as they quickly went with Flik to escape an inevitable beating from them. They aren't seen again for the rest of the film.
- Thud is a boss character in A Bug's Life: The Video Game.