How does a rat’s laugh sound? - briefly
Rats emit a high‑pitched, rapid series of chirps that sound like a squeaky giggle. The vocalization occurs during play or when tickled and consists of brief ultrasonic squeaks.
How does a rat’s laugh sound? - in detail
Rats produce a short, high‑pitched vocalization that resembles a squeaky, rapid chirp when they are tickled or engaged in playful interaction. The sound lasts roughly 30–100 ms and consists of a series of ultrasonic pulses that peak around 50 kHz, extending from 20 kHz to over 80 kHz. In the audible range (below 20 kHz) the emission is faint, often perceived as a soft “tch‑tch” or “squeak” by human listeners.
Researchers record these calls with ultrasonic microphones and analyze them using spectrogram software. Typical findings include:
- Fundamental frequency: 40–60 kHz during the most intense segment.
- Harmonic structure: prominent second harmonic at roughly double the fundamental, diminishing rapidly in amplitude.
- Modulation: slight upward frequency sweep of 5–10 kHz within each pulse, creating a “rising” quality.
- Inter‑pulse interval: 10–20 ms, producing a rapid succession that gives the impression of a giggle.
Behaviorally, the vocalization appears only in positive, socially rewarding contexts. When a rat receives gentle stroking or is exposed to a familiar conspecific’s tickling, the emission rate increases, sometimes reaching 10–15 calls per second. In contrast, distress or aggression elicit low‑frequency broadband squeals, lacking the structured ultrasonic pattern described above.
Comparative data show that Norway rats (Rattus norvegicus) and black rats (Rattus rattus) generate similar acoustic signatures, with minor variations in peak frequency (Norway rats average 55 kHz, black rats 48 kHz). Age influences amplitude: juveniles emit louder pulses, likely due to thinner vocal folds and higher respiratory pressure.
The combination of high pitch, brief duration, and rapid pulse train defines the characteristic “rat laugh.” Its ultrasonic nature explains why the sound is often unnoticed without specialized equipment, while the faint audible component accounts for occasional human perception of a tiny, squeaky chuckle.