Which one of the following adaptations allows certain moth families to escape predation by bats?

Correct Option

The correct option is

They can hear the high-frequency squeaks of the bat.

Explanation

Bats utilize echolocation, emitting high-frequency ultrasonic waves to navigate and locate prey. In response, certain prey species, particularly moths, have evolved sensory adaptations to detect these ultrasonic signals and evade predation. This is a classic example of predator-prey co-evolution involving acoustic competition.

Option Analysis

• They can fly faster than the speed of sound. is Incorrect: No biological organism, including moths, can fly faster than the speed of sound (approximately 343 meters per second). This is physically impossible for insects.
• They can hear the high-frequency squeaks of the bat. is Correct: Many moth families (such as Noctuidae and Geometridae) possess tympanal organs (ears) capable of detecting the ultrasonic frequencies (20 kHz to over 100 kHz) used by bats. Upon detecting these high-frequency squeaks, the moths perform erratic evasive maneuvers, such as power dives or spiraling, to escape the bat's trajectory.
• They emit infrasound to confuse the bats. is Incorrect: While some moths (e.g., Tiger moths) do emit sounds to confuse bats or warn of toxicity, they emit ultrasonic clicks, not infrasound. Infrasound consists of frequencies below the human hearing range (under 20 Hz), which is not relevant to bat echolocation.
• They have soft bodies that absorb ultrasonic waves. is Incorrect: While some moths have evolved scales that dampen sound reflection (acoustic camouflage), the description of "soft bodies" absorbing waves is not the primary or most distinct adaptation for escaping predation compared to the active sensory capability described in They can hear the high-frequency squeaks of the bat.. Furthermore, the absorption is primarily due to the structure of the scales, not the body softness itself.

Key Takeaway: Bats use ultrasound for echolocation. To survive, moths have evolved the ability to hear these ultrasonic frequencies, allowing them to initiate evasive flight patterns before the bat strikes.