How often have you caught your dog looking guilty or seen your cat basking in the sun with a contented glow? It’s interesting to assume that animals share our human emotions, but recent research reveals that some animals might actually exhibit a trait similar to laughter. Studies involving dogs, rats, chimpanzees, and other apes have documented unique sounds these species make in response to pleasure.

The historical context of animal laughter

The notion that animals might laugh isn’t new.

The idea dates back to Charles Darwin’s 1872 work, The Expression of Emotions in Man and Animals. Darwin observed chimpanzees and other apes responding to tickling and playing with sounds reminiscent of human laughter. Research conducted later at Germany’s University of Hannover supported Darwin’s findings, showing that these laughter-like sounds have evolved over the past 10-16 million years in primates.

Canine laughter: A breath of fresh air

In 2001, animal behaviorist Patricia Simonet identified a specific sound that dogs make exclusively during play, which she termed a “forced, breathy exhalation.” Through spectrograph analysis, Simonet compared this sound with other playful vocalizations like growling, whining, panting, and barking. The analysis showed that this laugh-like sound had a distinct spike compared to the flatter panting sound. Interestingly, when this recording was played for other dogs, they responded positively by seeking out toys or engaging in play behavior, indicating that they recognize and associate this sound with pleasure.

The chirps of happy rats
Rats also have their own form of pleasure sound. In the late 1990s, neuroscientist Jaak Panksepp from Bowling Green University observed that tickling baby rats produced a distinctive “chirp.” This high-frequency 50-kilohertz ultrasonic chirp was noted as different from other rat vocalizations. Panksepp’s findings suggested that this sound is linked to the rats’ play and joy.

Investigating laughter across species

While many animals seem to produce laughter-like sounds, it’s still uncertain if these are universally shared across species. Scientist Marina Davila-Ross from the University of Portsmouth has been exploring this concept by analyzing animal footage on YouTube. Her research shows that many animals make noisy responses when tickled, which might indicate joy, though it’s not yet confirmed as laughter in the human sense. While it’s heartwarming to think that our pets might enjoy a good chuckle, the mystery of who they’re laughing at remains an intriguing question.
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