Rats really do make laughter-like sounds when tickled, but their giggles are too high-pitched for human ears. During playful handling, they produce rapid ultrasonic chirps near 50 kilohertz. Researchers associate these calls with positive emotion, social play, and anticipation of rewards, rather than claiming they are identical to human laughter.
How scientists discovered it
The best-known experiments used “tickling” that mimicked the rough-and-tumble play young rats enjoy with one another. Scientists gently flipped rats onto their backs and tickled their bellies and sides. The animals responded with more 50-kilohertz calls, ran after the experimenter’s hand, and sometimes learned to seek another tickling session.
The American Museum of Natural History’s overview explains that rats also make lower, roughly 22-kilohertz calls when threatened or in pain. That contrast helps researchers interpret the higher chirps as signs of a positive state, although context and behavior still matter.
Not every rat wants tickles
Rats have individual personalities and preferences. Some chirp enthusiastically; others may freeze, pull away, squeak audibly, or avoid the hand. A responsible pet owner should let the rat choose whether to participate and stop immediately if the animal seems tense or tries to escape.
This discovery matters because it reveals that rats have richer emotional and social lives than many people assume. Their ultrasonic “laughter” gives scientists a way to study positive feelings and may help improve laboratory-animal welfare through gentler, more rewarding handling.
Want another animal surprise? Try this mammal vocal cords trivia question. Rat laughter may be silent to us, but it sends a clear message: tiny animals can experience playfulness, form social bonds, and actively seek interactions they enjoy. Sometimes joy is present even when human ears cannot detect it.
That makes the rat not just intelligent and sociable, but also one of nature’s most unexpected comedians.