When the moth hears a bat, it begins to fly erratically or stops flying and falls to the ground in order to confuse the enemy. This is shown in the montage: The moth nearest the bat has heard it and is falling down. The moth on the far right is not yet aware of the danger.
The evasive techniques of noctuid moths are effective. Once they detect the bat and react by flying erratically or falling down, they are almost impossible to catch, even though bats are
the great acrobats of the air.