A method for the extermination of burrowing vermin is disclosed. The method employs a smoke generating fluid formed of castor oil or castor oil in a mix with secondary components. The fluid is heated to a smoking temperature and the smoke is mixed with a pressurized airflow to communicate the smoke to the tunnels occupied by the burrowing vermin to remove them, and to leave a residue from the smoke which exudes an order deterring the re-occupancy of the tunnels.