A flight turned around shortly after takeoff following the sight of a rat loose inside the cabin.
The Loong Air flight had just left Hangzhou in China for the south-western city of Xishuangbanna, the airline said.
"Considering the threat to passenger health posed by the rat and the possibility of endangering flight safety by biting through wires, the captain flew back to port in the best interests of public health and safety," the airline said in a statement.
It is unclear how the rodent got onboard but news reports said it was not sneaked onto the aircraft as a pet.
The plane was grounded temporarily while it was extensively cleaned and fumigated.
Budget carrier Loong Air is based at Hangzhou and operates flights on more than 50 domestic routes in China.
