David Stipp’s “Why Rats Laugh & Jellyfish Sleep” is a breezy ode to nature’s long game. The respected science expert’s beautifully written book celebrates the adaptive ingenuity of animals whose ...

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 ...

To study play behaviors in animals, scientists must be able to authentically simulate play-conducive environments in the laboratory. Animals like rats are less inclined to play if they are anxious or ...