How do rats growl? - briefly
Rats emit a low, guttural growl by rapidly vibrating their vocal cords while exhaling, often with a slight throat constriction. The sound functions as a warning or territorial signal during confrontations.
How do rats growl? - in detail
Rats are capable of emitting low‑frequency vocalizations that sound like growls. These sounds differ from the high‑pitched squeaks commonly associated with the species and serve specific communicative functions.
The larynx of a rat contains thin, pliable vocal folds that can vibrate when air passes from the lungs. Contraction of the diaphragm and intercostal muscles increases subglottal pressure, forcing airflow through the glottis. By adjusting the tension of the vocal folds and the size of the glottal opening, the animal modulates the vibration frequency, producing a deep, rough tone.
During a growl, the rat typically lowers the position of the larynx and tightens the vocal folds, which reduces the fundamental frequency to the range of 200–600 Hz. The sound is often accompanied by a brief, irregular pulse pattern that creates a harsh timbre. Duration varies from 0.2 to 1 second, and the waveform includes strong harmonics that give the vocalization its characteristic raspiness.
Growling occurs most frequently in aggressive encounters, when a rat defends territory, or during dominance contests. The sound signals threat and can deter rivals without resorting to physical confrontation. It also appears in defensive situations, such as when a rodent confronts a predator or perceives a sudden threat.
Research on these vocalizations relies on high‑sensitivity microphones capable of capturing both audible and ultrasonic components. Recordings are analyzed with spectrogram software to extract frequency, amplitude, and temporal patterns. Controlled experiments often pair acoustic monitoring with behavioral observation to correlate growl production with specific social interactions.
In summary, rats generate growling sounds through coordinated laryngeal muscle activity that lowers vocal fold tension and increases airflow pressure, resulting in low‑frequency, harsh vocalizations used primarily for aggression and defense.