Despite what movies would have you think, rats barely ever make any sounds, at least those that humans are able to hear. Rat’s vocalizations start at around 2 kHz and extend as far up as 100 kHz. For reference, human’s can hear roughly 2-20 kHz, so the vast majority of rat noises made are well into the ultrasonic spectrum. Pet and wild rats alike will seem almost mute, unless put into extreme distress, when they will squeak or shriek audibly. If you record rats with an ultrasonic microphone however, you find that they actually make many noises, to convey everything from joy to dominance and even to laugh!