Key Takeaways
- •Rats communicate primarily in ultrasonic frequencies (20kHz-100kHz) that humans can't hear
- •50kHz calls = happy/playful — this is their 'laughing' frequency
- •22kHz calls = distress, fear, or pain
- •Audible bruxing (teeth grinding) = contentment when being petted
- •Audible squeaking usually means surprise, pain, or protest
- •Clicking or crackling breathing sounds = potential respiratory infection — see a vet
The Hidden World of Rat Communication
Here's something remarkable that most rat owners don't know: your rats are constantly talking to each other — and to you — in frequencies you cannot hear.
Rats communicate extensively in the ultrasonic range (above 20kHz, where human hearing ends). They produce two main types of ultrasonic vocalizations:
50kHz calls: Associated with positive emotional states. Rats make these during play, when exploring interesting environments, when tickled (yes, rats can be "tickled"), and during social bonding activities. Researchers describe these as functionally analogous to laughter.
22kHz calls: Associated with negative emotional states — distress, fear, pain, anticipation of something unpleasant. A rat about to face something scary (like a visit to the vet) will produce 22kHz calls. So will a rat in pain.
You cannot hear either of these. Your rats are having entire conversations you're completely missing.
Why This Matters
Research in the field of rodent ultrasonic vocalization has shown that 50kHz call rates are reliable indicators of rat wellbeing. Rats who make more 50kHz calls tend to be healthier, happier, and live longer. Rates drop during illness, chronic stress, and aging.
This behavioral data — this constant stream of ultrasonic communication — contains information about your rat's emotional and physical state that no amount of visual observation can provide.
“I have been broadcasting my happiness in 50kHz frequencies for three years. You've been missing all of it. ElovioPet is going to change this relationship significantly.”
Audible Rat Sounds and What They Mean
Bruxing (Teeth Grinding)
This is the audible sound most rat owners encounter first. A soft, rhythmic clicking or grinding of the teeth that you can feel as vibration when you hold your rat.
Bruxing during petting and social interaction = contentment. The rat equivalent of a purr.
At the extreme end of bruxing contentment, the vibration transmits to the eye sockets, causing visible "boggling" — the eyes appearing to vibrate in their sockets. This is peak happiness.
See our body language guide for more on bruxing vs. boggling.
Audible Squeaking
Unlike the soft bruxing, an audible squeak is louder and more clearly vocalized:
Surprise squeak: Brief, one-off — "you startled me" Pain squeak: Repeated, often when touched in a sensitive area or during movement Protest squeak: When being restrained for nail trimming, being moved somewhere they don't want to go Fear squeak: In new environments or situations, often combined with escape attempts
Context differentiates these. A single surprise squeak is different from repeated squeaking during normal handling.
Hissing
Rare in rats compared to hamsters or guinea pigs. A hissing rat feels seriously threatened. Give them space.
Chattering
Rapid teeth chattering — different from soft bruxing — is a threat or stress signal. May occur during vet visits, introduction to unfamiliar rats, or highly stressful situations.
Soft Chirps and Vocalizations
Some rats produce audible chirps during play or exploration. These are positive social vocalizations — a softer, more melodic sound than a squeak. Some owners report their rats chirping when reunited with them after a period apart.
The Sound That Demands Attention: Respiratory Clicking
Separate from all vocalizations: any clicking, crackling, rattling, or wheezing sound coming from your rat's chest or nose during normal breathing is a potential respiratory symptom.
This is not a vocalization — it's a breathing sound caused by airway inflammation, mucus, or lung damage. Given that virtually all pet rats carry Mycoplasma pulmonis (the primary rat respiratory pathogen), any unusual breathing sound warrants a vet evaluation.
Hold your rat close to your ear and listen to their breathing during calm rest. It should be quiet and smooth.
If you hear:
- Clicking with each breath
- Crackling or rattling
- Labored, effortful breathing
- Wheezing
Schedule a vet appointment. Early treatment is far more effective than waiting.
Read our respiratory infections guide for more.
🩺
Have a concern about your rat?
Browse our species-specific care guides for expert advice on diet, housing, health, and behavior.
Explore Care Guides