What Sounds Do Domestic Rats Make?

The Acoustic World of Pet Rats

Understanding Rat Vocalizations

Types of Rat Sounds

Domestic rats communicate through a spectrum of vocalizations that convey emotional state, intent, and social hierarchy. Each sound carries a specific acoustic signature and is emitted in predictable contexts, allowing observers to interpret rat behavior accurately.

High‑frequency squeak – brief, sharp bursts produced when a rat is startled or in pain; frequency often exceeds 20 kHz, making it partially ultrasonic.
Chirping (or “twitter”) – rapid, repetitive notes emitted during play or excitement; amplitude is moderate, and the pattern is rhythmic.
Teeth chattering – rapid clattering of incisors, signaling aggression, territorial defense, or heightened alertness; audible in the 2–5 kHz range.
Ultrasonic calls – frequencies above human hearing (30–80 kHz) used for mother‑pup bonding, courtship, and subtle social signaling; recorded with specialized equipment.
Purring (soft, continuous rumble) – low‑intensity vibrations produced while a rat is relaxed or content, often accompanied by gentle body movements.
Whining – prolonged, high‑pitched tone indicating distress, separation anxiety, or a request for attention; intensity rises with the severity of the stimulus.
Growl – deep, resonant sound associated with defensive posturing or warning; typically follows a visual threat display.

These categories encompass the primary acoustic repertoire of pet rats, enabling precise assessment of welfare and interaction dynamics.

Reasons for Vocalizations

Domestic rats produce a variety of vocalizations that serve distinct functional purposes. Each sound conveys information about the animal’s internal state or external environment, enabling efficient interaction within the colony.

Alarm calls – high‑frequency squeaks emitted when a threat is detected; prompt conspecifics to flee or hide.
Distress cries – prolonged, low‑frequency noises released during pain, injury, or isolation; signal vulnerability and elicit assistance from cage mates.
Social chatter – short, ultrasonic chirps exchanged during grooming, play, or nest building; reinforce social bonds and coordinate cooperative activities.
Mating vocalizations – specific patterns of squeaks and clicks produced by both sexes during courtship; facilitate partner recognition and synchronize reproductive behavior.
Territorial signals – rhythmic squeals uttered when an individual defends a preferred nesting area; deter intruders and maintain spatial hierarchy.
Food‑related sounds – brief, high‑pitched notes emitted while exploring or consuming novel items; communicate discovery and encourage group feeding.
Developmental calls – ultrasonic peeps produced by pups to solicit maternal care; decrease as the young mature and acquire independence.
Health indicators – alterations in call frequency, duration, or intensity can reflect physiological stress, infection, or metabolic disturbances; serve as early markers for veterinary assessment.

These vocal categories illustrate how acoustic output functions as a versatile communication system, allowing domestic rats to navigate social structures, reproductive cycles, predator avoidance, and environmental challenges.

Common Rat Sounds and Their Meanings

Ultrasonic Vocalizations (USVs)

50-kHz USVs: Positive Emotions

Domestic rats emit ultrasonic vocalizations (USVs) around 50 kHz when they experience rewarding or pleasant situations. These calls are brief, frequency‑modulated bursts that peak near 50 kHz and can last from 10 ms to several hundred milliseconds. Their acoustic structure differs from the 22‑kHz calls linked to aversive states, displaying higher pitch, rapid modulation, and a harmonic-rich spectrum.

Experimental recordings reveal that 50‑kHz USVs appear during:

Social play among juveniles
Courtship and mating encounters
Anticipation of food or water after a learned cue
Exploration of novel, rewarding environments

The frequency and rate of emission increase with the intensity of the positive stimulus. For example, rats trained to associate a tone with a sucrose reward produce a surge of 50‑kHz calls immediately after tone presentation, indicating expectation of pleasure.

Neurophysiological studies connect these vocalizations to dopaminergic activity in the nucleus accumbens and ventral tegmental area. Pharmacological blockade of dopamine receptors reduces both the occurrence of 50‑kHz USVs and the associated approach behavior, confirming a link between dopamine signaling and the expression of positive affect.

In laboratory settings, researchers use automated detection of 50‑kHz USVs as an objective metric of affective state. The method provides real‑time assessment of welfare, allowing rapid identification of conditions that enhance or diminish rat well‑being.

22-kHz USVs: Negative Emotions

Rats emit ultrasonic vocalizations in the 22‑kHz range when experiencing aversive states. These calls are brief, downward‑frequency sweeps lasting from a few hundred milliseconds to several seconds, with peak amplitudes around 80–90 dB SPL at the source. The acoustic profile distinguishes them from the higher‑frequency (≈50 kHz) calls associated with positive or exploratory behavior.

Typical situations that trigger 22‑kHz USVs include:

Exposure to predator odor or actual predator presence.
Administration of painful stimuli such as foot‑shocks or tail pinches.
Social defeat, isolation, or defeat in a dominance hierarchy.
Anticipation of an unavoidable aversive event, for instance a scheduled shock.

Physiological correlates accompany these vocalizations. Elevated corticosterone levels, increased heart rate, and heightened sympathetic activity are consistently recorded during 22‑kHz emission. Neurochemical studies link the calls to activation of the amygdala and periaqueductal gray, regions governing fear and pain processing.

Research applications exploit the reliability of 22‑kHz USVs as a non‑invasive indicator of negative affect. They serve as behavioral endpoints in analgesic testing, anxiety‑related pharmacology, and models of depression. Quantitative analysis of call frequency, duration, and inter‑call interval provides objective metrics for assessing the efficacy of interventions aimed at reducing distress.

In summary, 22‑kHz ultrasonic vocalizations function as a precise acoustic marker of adverse emotional states in domestic rats, reflecting underlying neurophysiological processes and offering a valuable tool for experimental investigation.

Audible Vocalizations

Squeaks

Domestic rats produce a range of high‑frequency vocalizations that humans commonly describe as squeaks. These sounds serve as immediate signals of the animal’s internal state and environmental interactions.

Alarm squeak – short, sharp burst lasting 0.05–0.1 seconds; emitted when a rat perceives a sudden threat or is startled. Frequency peaks between 20–30 kHz, often beyond human hearing but audible as a faint chirp in the lower range.
Excitement squeak – longer series of rapid pulses, each 0.02–0.05 seconds, repeated at a rate of 10–15 Hz. Occurs during play, exploration of novel objects, or when the rat anticipates food. Acoustic energy concentrates around 15–25 kHz.
Distress squeak – prolonged, monotone tone lasting up to several seconds. Characterized by lower pitch (10–15 kHz) and reduced modulation. Signals discomfort, injury, or isolation.
Social squeak – brief, modulated chirp used in close‑range communication between cage mates. Duration 0.03–0.07 seconds, with frequency sweeps from 18 to 28 kHz, facilitating identification and hierarchy establishment.

Context determines the acoustic pattern. An alarm squeak appears abruptly after a loud noise; an excitement squeak follows the introduction of a new tunnel; a distress squeak may accompany a prolonged period of separation from conspecifics. Frequency analysis shows that domestic rats modulate both pitch and temporal structure to convey specific information, allowing caretakers to infer welfare conditions without visual observation.

Chattering and Teeth Grinding («Bruxing»)

Domestic rats produce a distinctive high‑pitched chatter when they are excited, agitated, or engaged in social interaction. The sound consists of rapid, repetitive clicks generated by rapid closure of the jaw, often accompanied by a trembling of the whiskers. In a familiar environment, chattering signals anticipation of food, play, or territorial display; in an unfamiliar setting, it can indicate heightened alertness or defensive posture.

Teeth grinding, commonly termed bruxing, appears as a continuous, low‑frequency grinding noise produced by the incisors rubbing together. This behavior occurs primarily during periods of rest or sleep and is associated with the rat’s natural dental maintenance. Bruxing also manifests when an animal experiences mild stress or is adjusting to a new cage, serving as a self‑soothing mechanism.

Both vocalizations convey information without visual cues. Chattering is typically audible at a distance of 1–2 meters and may reach frequencies between 6 kHz and 12 kHz, whereas bruxing generates frequencies below 5 kHz and can be felt as vibrations through cage walls. Recognizing these sounds enables caretakers to assess the animal’s emotional state, health, and comfort level.

Hissing

Domestic rats emit a sharp, low‑frequency hiss that serves as an immediate warning signal. The sound is produced by forceful expulsion of air through the nasal passages, creating a rapid, raspy vibration audible at 2–5 kHz. Hissing is typically accompanied by a stiffened posture, flattened ears, and a raised tail, indicating heightened arousal.

Common triggers for hissing include:

Perceived threat from humans or other animals
Intrusion into a confined space where the rat feels cornered
Sudden loud noises or abrupt movements near the enclosure
Competition over food or nesting resources

The hiss differs from other rat vocalizations such as ultrasonic chirps or high‑pitched squeaks. While ultrasonic calls convey social bonding or distress, the hiss operates at an audible range and conveys aggression or defensive intent. Frequency and duration vary with the intensity of the stimulus; a brief, low‑volume hiss may accompany mild annoyance, whereas a prolonged, louder hiss signals severe stress or imminent attack.

Understanding the hissing pattern helps caretakers assess welfare. A sudden increase in hiss frequency often precedes aggressive encounters, prompting interventions such as providing additional hiding spaces, reducing handling stress, or separating conflicting individuals.

Chirping

Domestic rats emit several vocalizations; chirping stands out as a high‑pitched, rapid sound distinct from ordinary squeaks. Researchers record chirps at frequencies between 10 and 20 kHz, lasting 0.1–0.3 seconds, often repeated in quick succession.

Rats produce chirps primarily during moments of heightened excitement. Typical triggers include:

Introduction of a novel object
Anticipation of food
Playful interaction with cage mates
Exposure to a favored human voice

The acoustic profile of a chirp features a steep rise in amplitude, a narrow bandwidth, and a clear tonal quality. Unlike the low‑frequency grunt used in aggressive encounters, chirps convey positive arousal and are often accompanied by rapid whisker movement.

In addition to chirping, rats generate:

Short squeaks (30–40 kHz) linked to distress
Teeth‑chattering sounds (5–10 kHz) indicating aggression or territorial behavior
Soft rustling noises during grooming

Understanding chirping helps differentiate benign excitement from stress‑related vocalizations, facilitating more accurate assessment of pet rat welfare.

Interpreting Rat Sounds: A Guide for Owners

What to Listen For

Domestic rats communicate through a limited but distinct set of vocalizations. Recognizing each sound helps assess health, stress level, and social interaction.

High‑pitched squeaks – brief, sharp bursts emitted when a rat feels threatened or startled. Frequency often exceeds 20 kHz, audible to humans as a rapid “peep.”
Soft chirps or “tweet” sounds – gentle, rhythmic notes produced during exploration or when a rat is content. Typically heard when the animal is sniffing new objects or interacting with a familiar companion.
Teeth chattering – rapid, metallic clicks indicating agitation, discomfort, or a warning to other rats. Occurs during territorial disputes or when a rat is restrained.
Ultrasonic calls – frequencies above 20 kHz, invisible to the human ear but detectable with specialized equipment. These calls convey social information such as mating readiness, hierarchy, and maternal bonding.
Low‑frequency growls or rumblings – deep, resonant sounds associated with aggression or defensive behavior. Often accompany a stiff posture and raised fur.

Each vocalization corresponds to a specific behavioral context. Monitoring these cues provides reliable insight into a pet rat’s emotional state and physical condition.

When to Seek Veterinary Advice

Pet rats use a variety of vocalizations—squeaks, chirps, teeth chattering, and audible breathing—to express comfort, distress, or illness. A sudden shift in these sounds often signals a medical problem that requires professional assessment.

High‑pitched, continuous squeaking that replaces brief, intermittent calls
Loud, persistent wheezing or rattling during respiration
Uncharacteristically low, guttural growls when the rat is normally quiet
Sudden onset of teeth‑chattering without an obvious trigger

These acoustic changes, especially when paired with other clinical signs, indicate the need for veterinary care.

Additional indicators that strengthen the case for a vet visit include loss of appetite, rapid weight loss, lethargy, abnormal stool, visible sores, or a change in grooming behavior. When any of these accompany the abnormal sounds, immediate consultation is advised.

Contact a veterinarian experienced with small mammals promptly. Provide a description of the sound pattern, duration, and any accompanying symptoms. The clinician will likely perform a physical exam, respiratory assessment, and may request diagnostic imaging or laboratory tests to determine the underlying cause. Early intervention improves prognosis for respiratory infections, dental disease, and other common rat health issues.

Factors Influencing Rat Vocalizations

Age and Development

Domestic rats produce distinct vocalizations that evolve as the animal matures. Newborn pups (0–10 days) emit high‑frequency ultrasonic clicks, typically 40–70 kHz, generated by the larynx and used to stimulate maternal care. These clicks are brief (10–30 ms) and increase in rate when pups are separated from the dam.

During the weaning period (10–21 days) rats begin to produce low‑frequency audible squeaks (approximately 2–5 kHz). Squeaks accompany mild stress, handling, or social interaction and serve as immediate distress signals. The acoustic structure becomes more complex, with modulation of pitch and duration reflecting the animal’s growing nervous system.

Juvenile rats (3–6 weeks) add ultrasonic chirps (around 22–50 kHz) to their repertoire. Chirps are emitted during play, exploration, and social bonding, indicating a positive affective state. Frequency modulation and harmonic content become more elaborate, allowing discrimination between individual conspecifics.

Adult rats (≥8 weeks) display a full spectrum of sounds:

Ultrasonic vocalizations (USVs): 22 kHz calls associated with aggression or territorial threats; 50 kHz calls linked to reward and mating.
Audible squeaks: brief, high‑amplitude bursts during acute pain or sudden threats.
Purr‑like rumblings: low‑frequency vibrations produced during grooming or contentment, often below the human hearing threshold.

Aging rats (≥18 months) show reduced call frequency and amplitude. Ultrasonic output declines, with a shift toward lower frequencies and longer inter‑call intervals. Vocal fatigue appears during prolonged social interaction, reflecting age‑related changes in respiratory and laryngeal musculature.

Overall, rat vocal behavior follows a predictable developmental trajectory: neonatal ultrasonic clicks, juvenile chirps, adult USVs and audible squeaks, and a gradual attenuation of acoustic performance in senior individuals.

Social Context

Domestic rats rely on a rich acoustic repertoire to navigate social interactions, establish hierarchy, and coordinate group activities. Each vocalization conveys specific information about the emitter’s status, intent, or emotional state, allowing colony members to respond appropriately without visual cues.

Ultrasonic chirps (50–80 kHz): Emitted by pups when separated from the mother; trigger retrieval behavior and reinforce maternal bonding.
High‑frequency “trills” (30–50 kHz): Produced by adults during exploratory play; indicate a non‑threatening, affiliative mood and invite reciprocal interaction.
Mid‑frequency “whines” (10–30 kHz): Associated with mild distress or social frustration; often precede submissive postures and can de‑escalate potential aggression.
Low‑frequency “growls” (5–10 kHz): Convey dominance or territorial warning; commonly heard during confrontations over food, nesting sites, or mating opportunities.
Complex “rat chatter” (mixed frequencies): Occurs during courtship; combines ultrasonic and audible components to attract mates and synchronize reproductive readiness.

The context in which these sounds arise determines their function. During group feeding, low‑frequency growls suppress competition, while high‑frequency trills maintain cohesion. In nesting chambers, ultrasonic pup calls sustain maternal attention, whereas adult whines may signal overcrowding or resource scarcity, prompting redistribution of individuals. Mating pairs exchange a patterned sequence of whistles and trills that coordinate courtship advances and reciprocal acceptance.

Understanding these acoustic signals provides insight into the hierarchical structure, reproductive strategies, and stress management within domestic rat colonies. Researchers and caretakers can use vocal monitoring to assess welfare, detect early signs of conflict, and facilitate environments that align with the species’ innate communication system.

Environmental Factors

Domestic rats alter their vocal repertoire in response to measurable changes in their surroundings. Temperature shifts can suppress low‑frequency growls while encouraging high‑frequency squeaks that travel efficiently in warmer air. Light intensity influences activity cycles; dim conditions often precede ultrasonic chirps associated with exploration, whereas bright periods increase audible chatter during foraging.

Ambient temperature
Light cycle and intensity
Social density (number of conspecifics)
Enclosure dimensions and complexity
Substrate texture and material
Relative humidity
Time of day (circadian phase)
Human presence or perceived threat

Higher social density raises the frequency of contact calls and short squeaks used for coordination, while isolated individuals emit longer, more tonal whistles. Complex habitats with tunnels and nesting material stimulate exploratory chirps that exceed the human hearing range. Elevated humidity dampens ultrasonic transmission, prompting rats to rely on audible squeaks for communication. Sudden disturbances, such as a hand entering the cage, trigger abrupt, high‑amplitude vocalizations that signal alarm.

Understanding these environmental determinants enables owners to interpret auditory cues accurately and allows researchers to standardize conditions when recording rat vocalizations. Adjusting temperature, lighting, and cage enrichment yields reproducible sound patterns, facilitating reliable behavioral assessments.