To actualize a method for controlling bird egg hatching, with which bird egg hatching is controlled in a state of bird eggs in a nest.

Firstly, a tank 3 is charged with 5 liters of a surfactant diluted in twice the volume. An operator of a radio-controlled helicopter 1 operates a transmitter for radio control and guides the radio-controlled helicopter 1 to above the nest of cormorants while monitoring a downward appearance in the advance direction by a camera 6 and keeps the helicopter at a spot about 2 meters above the nest. Then, the operator operates an aerial application controller not shown in the figure and performs aerial application of the surfactant. When the aerial application controller receives a control signal by an aerial application antenna 12, the aerial application controller adjusts the application amount of the liquid on the basis of the control signal by a generally known control method using a pump, a motor, etc., not shown in the figure, supplies the liquid charged in the tank 3 through a liquid supply tube to a nozzle 5 and performs aerial application.