A jet of the Australian national carrier Qantas was forced to stay on ground after rats were found in a cabin compartment on board.According to local media reports, the flight attendants found five rats in the cabin of a Boeing 767 flying from Sydney to Brisbane on Wednesday, minutes before passengers were due to board.Calling it a rare occurrence, the airline said the passengers were put on another plane while the rats were disposed of.Qantas is unsure of how the rats got on board.