(i) What does the acronym SONAR stand for ? (ii) What is the audible range of sound for human beings ? (iii) How do the bats search and catch their prey in dark night?

(i) Sound Navigation And Ranging.
(ii) 20 Hz to 20,000 Hz.
(iii) The high-pitched ultrasonic squeaks of the bat are reflected from the obstacles or prey and returned to the bat7 s ear. Such reflections inform the bat where the prey is and what it is like.