A new study in the journal Bioacoustics found that 65 different species of animals have their own form of laughter. Study co-author Sasha Winkler describes the sounds animals make during play.

If you tickle a rat's belly, it squeals with laughter. However, we are unable to perceive this laughter as its frequency, around 50 kHz, exceeds the range of human hearing. Neuroscientist Jaak ...

Among humans, laughter can signify a lot of different things, from intimacy to discomfort. Among animals, however, laughter usually communicates something along the lines of “this is playtime—I’m not ...