About 96% of Scandinavian moths have ears tuned to the ultrasonic pulses that bats, their predators, emit. But the remaining 4% do not have ears and are deaf. However, they have a larger wingspan than the hearing moths, and also have higher wing-loadings-the ratio between a wing's area and its weight-meaning higher maneuverability.
Which one of the following can be best inferred from the above passage?