It’s International Joke Day, but let’s get serious. Evidence suggests a good laugh is great for our health. But what if you just don’t feel funny? Can tickling help?

That’s where research comes in. Dr Shimpei Ishiyama is studying tickling and laughter in rats. It turns out, anyone can learn to tickle a rat, he says.

“It is very easy…though there are some techniques, such as flipping them and tickling the belly, which you may need to practice a bit.”

Shimpei is studying the way rats’ brains react to a good tickling. He hopes to learn more about how our own brains work.

“Our results suggest that ticklishness has been conserved through evolution, and is related to playfulness. We speculate ticklishness is perhaps a brain’s trick to make us play with others, and have fun,” he says.

Ready, set, tickle

Shimpei and his team of ticklers have even noticed differences in rat personalities. Shy rats tend to laugh less, while playful rats laugh more.

Shimpei loved being tickled as a kid, but now he hates it. “It is also the same for rats. Young rats enjoy being tickled, while adult rats are annoyed,” he says.

Top tickler’s tip:

Before you attempt to tickle your rat, take a deep breath. It’s important that you’re feeling relaxed and friendly.

“Rats…can sense the stress hormone in sweat on my palm, which could potentially make them nervous,” says Shimpei.

Is your rat missing its sense of humour?

Worried that your rats are too serious? Don’t worry. It’s normal to feel this way. And it could be your rats are having a super time, you just don’t realise.

Rats laugh at ultrasonic frequencies, so the human ear cannot hear their giggles.

I originally wrote this article for CSIRO’s Double Helix magazine 🙂