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 ...

Tickling is strange because it does not feel optional. You do not decide to laugh. Your body just does it. The sound comes out before your brain has time to judge whether anything is funny. People ...

A new study is linking brain behavior to silly playtime practices. And they have lab rats laughing out loud to prove it.In the video above, you can hear tiny high-pitched giggles from a rat being ...