Humans aren’t the only animals with a sense of humor, but you might not recognize the guffaws of the rest of the animal kingdom. Primates, dogs, and rats can all express high spirits through laughter, especially if they're tickled. In doing so, each makes a slightly different sound than the human ha ha ha. Here’s how to recognize a laugh in the wild:
Apes—like chimpanzees, gorillas, bonobos, and orangutans—can laugh. In some, it sounds like panting, while others sound more like grunts or even purrs.
Listen to how chimps laugh above, and compare it to the gorilla and orangutan below:
In one study of captive chimpanzees, chimps produced panting sounds when surprised by a playmate. Occasionally, the playmate panted back—chuckling along with their friend’s laughter. Non-human primates even seem to be able to crack jokes. Peter McGraw and Joel Warner, authors of the book The Humor Code: A Global Search for What Makes Things Funny, report:
Koko, a gorilla in Woodside, Calif., who has learned more than 2,000 words and 1,000 American Sign Language signs, has been known to play with different meanings of the same word. When she was asked, ‘What can you think of that’s hard?’ the gorilla signed, ‘rock’ and ‘work.’ She also once tied her trainer’s shoelaces together and signed, ‘chase.’
Dogs don’t just pant because they’re out of breath. A long, loud pant can also be the sound of a pooch’s laugh. The sound of other dogs’ laughing pants seems to calm canines. One Washington animal shelter began playing the sound of laughing dogs over the loudspeaker in an attempt to calm the resident dogs. All 15 dogs reportedly went quiet at the sound.
This dog owner recorded what seems to be two dogs laughing as they play:
Rodents can laugh, but they do so beyond the range of human hearing. When tickled, especially at the nape of the neck, rats make noises in the ultrasonic range that scientists have deduced is the equivalent of laughter [PDF]. They also make these high-pitched chirps when they play. In one experiment, rats who had been tickled followed the human hand that had done the tickling, seeking out more play time. The most ticklish rats were also the most naturally playful.
4. Boring Birds
Unfortunately, just because an animal sounds like it’s laughing doesn’t mean it’s expressing joy at your latest wisecrack. Australia’s laughing kookaburra is named after the sound of its call, which sounds like an evil genius laying out a nefarious plan. But the kookaburra doesn’t find anything funny—at least nothing that science can measure.
So don’t worry, the birds aren't laughing at you. But the dog? The dog is definitely laughing behind your back.