Passage: 'Echolocation is a biological sonar utilized by microbats, toothed whales, and certain cave-dwelling birds to navigate and forage in total darkness. By emitting high-frequency sound pulses and interpreting the returning acoustic echoes, these animals construct a high-resolution mental map of their immediate environment. Some bats can perceive target objects as thin as a human hair and calculate the flight speed and trajectory of flying insects within fractions of a second.' What is the primary function of echolocation described in the passage?