MCQ Detailed View

Bats are nocturnal mammals that are able to fly and hunt effectively even in complete darkness. They achieve this extraordinary ability by using ultrasonic waves. Ultrasonic waves are sound waves with frequencies higher than the upper limit of human hearing (above 20,000 Hz). Humans cannot hear these sounds, but bats can produce and detect them easily.

This biological phenomenon is known as echolocation. When a bat flies, it emits a series of ultrasonic sound pulses through its mouth or nose. These sound waves travel through the air, strike objects, and bounce back as echoes. The bat’s highly sensitive ears can detect these returning echoes and analyze their time delay and direction. This process allows the bat to form a mental "sound map" of its surroundings, helping it detect obstacles, locate prey such as insects, and navigate safely even in complete darkness.

Option 1, ultraviolet waves, refers to a type of light that some animals can see, but bats do not rely on ultraviolet light for navigation in the dark. Option 3, electromagnetic waves, is a broad term covering radio, light, and X-rays, which are not used by bats for flying in the dark. Option 4, special retina, is incorrect because bats do not depend primarily on vision to move in darkness; instead, their echolocation system is far more efficient than eyesight in the absence of light.

Thus, the correct answer is Option 2: Ultrasonic Waves, as this sound-based navigation is a key biological adaptation in bats that enables them to fly, hunt, and avoid obstacles during the night.