The crew of the Airbus A-321, operating flight AI-021 from Kolkata, found a rat in the rear of the aircraft, airline sources said.
As soon as the flight landed and the passengers had deplaned, the aircraft was taken off service and removed for fumigation to a remote bay.
Rodents are unwelcome guests who pose a serious threat to an aircraft as they can chew up and damage the hundreds of wires on a plane.
The sources said they suspect the rats came from the catering vans which deliver food to the aircraft.
There have been cases in the past few years in which rats have reportedly delayed some domestic flights.