Answer: He gets expelled from the island.
He had previously been expelled from the island, but the other ants told Flik to find warrior bugs. The other ants, except for Dot, thought he would never find any warrior bugs that would want to help ants so they thought that by doing this, they were getting rid of Flik forever. He returns with a group of bugs that he thinks are warrior bugs and he tells the other ants that. Then, the other ants ask the child ants to make a mural of the "Warrior bugs" killing the grasshoppers, and then they do a play showing the warriors killing the grasshoppers, the circus bugs confess to Flik that they are circus bugs not warrior bugs. This makes both Flik and the circus bugs angry, each of whom felt that the other lied to them. So, the circus bugs tried to leave the island and Flik tries to encourage them to stay, but they only retreat back to Ant Island when they are chased by a bird. When they get back to the island, Flik gets an idea for all the ants and circus bugs to build a fake bird that can be operated like an airplane, and Flik says it was the idea of the "Warrior bugs". At this point in time, Flik was the only ant who knew that the "Warrior bugs" were really circus bugs. Then, P.T. Flea comes to the island looking for the circus bugs and reveals their secret. Initially, the other ants are mad at the circus bugs, thinking that they lied about being warrior bugs and that the bird idea was their idea. Francis the ladybug tells them that it was Flik's idea. Then, the other ants, except Dot, turn their outrage on Flik. Flik had lied to them about what kind of bugs he had brought back and he had also lied to them about whose idea it was to build a fake bird. The other ants never knew that Flik really did think he brought back warrior bugs at first and didn't found out later (but even after Flik found out the truth, he had continued lying about what kind of bugs those were). Flik is then told to leave and never come back. Flik is forced to join the circus.