After Bart make his apology , the Parliament reveal that they want to give him the additional punishment of a " booting " , which is a kick in the buttocks using a giant boot . Bart and Homer escape and the family flee to the American Embassy . After a prolonged standoff , the two governments propose a compromise to the Simpson family : one kick from the Prime Minister , through the gate of the embassy , with a regular shoe , believed to be a wingtip . Marge is opposed to the idea , but Bart agree . However , Bart dodge the kick , moon the Australians with the words " don 't tread on me " written on his buttocks , then hums " The Star @-@ Spangled Banner " . In a scene reminiscent of the Fall of Saigon the Simpson family flee the outraged country in a helicopter . Looking down on Australia , they see that bullfrogs have begun to overpopulate and destroy the Australian ecosystem , due to a bullfrog Bart left earlier at the airport . Viewing the devastation , the family remark upon the destruction that can be caused by introducing a foreign species into a new environment , and laugh at the Australians ' misfortune , unaware that a koala is hanging onto the helicopter . The camera zoom in on the koala , ending with a close @-@ up of its eye , implying that America will face a similar fate as Australia .