What do the sounds made by rats mean? - briefly
Rats produce specific vocalizations: high‑frequency squeaks signal distress or threat, low‑frequency chirps convey social bonding or curiosity, and ultrasonic clicks accompany mating or territorial behavior.
What do the sounds made by rats mean? - in detail
Rats communicate through a range of vocalizations that convey specific information about their environment, social status, and physiological state. The sounds are produced by rapid movements of the larynx and can be classified by frequency, duration, and context.
Ultrasonic squeaks (above 20 kHz) dominate most interactions. When a rat emits short, high‑frequency chirps while exploring, the signal indicates curiosity and low threat. Longer, modulated ultrasonic calls accompany social play, signaling invitation and positive affect. In aggressive encounters, rats produce a series of rapid, broadband squeals that increase in amplitude; these calls function as warnings and can trigger retreat in conspecifics.
Audible vocalizations (below 20 kHz) appear in distinct situations. A sharp, low‑pitched squeak during restraint or painful stimuli serves as an alarm, prompting immediate attention from nearby rats. A sustained, low‑frequency growl accompanies territorial defense, reinforcing dominance and deterring intruders.
Additional vocal patterns include:
- Purr‑like trill: Soft, continuous sound emitted during grooming or close contact; indicates relaxation and bonding.
- Whine: High‑pitch, drawn‑out tone during separation from littermates; reflects distress and a desire for reunion.
- Chatter: Rapid series of clicks produced while chewing or feeding; unrelated to social communication, reflects mastication activity.
The acoustic structure of each call correlates with physiological measurements. Elevated heart rate and cortisol levels accompany alarm calls, whereas reduced autonomic activity aligns with purr‑like trills. Playback experiments demonstrate that rats modify their behavior in response to recorded sounds: exposure to ultrasonic play invitations increases approach behavior, while exposure to distress calls elicits freezing or escape.
Understanding these vocal signatures enables precise assessment of rat welfare, improves experimental design, and informs pest‑management strategies by allowing targeted acoustic deterrents.