Ability of a bat to detect small objects Bats emit ultrasound in order to detect prey. Ultrasound has a much smaller wavelength than sound, which improves the resolution of small objects. What is the diameter of the smallest object that forms a diffraction pattern when irradiated by the $8.0 \times 10^{4}$ -Hz ultrasound from a bat? The first diffraction minimum from the smallest object is $90^{\circ} .$