This Just Makes Me Happy

Rats Tickled Pink With New Rodent Laughter Research

Associated Press

BOWLING GREEN, Ohio - Rats just want to have fun.

The fact that rats can laugh, and do, is nothing new to scientists, but a researcher at Bowling Green State University found that the rodents most people consider filthy pests are also playful - and love to be tickled.

"About a year ago, I literally came into the lab one morning and said, 'Let's go tickle some rats,"' said Jaak Panksepp, a psychobiologist. "As soon as we did it, it was 'Eureka!' This vocalization came on right away, and more intense than before. And the data have literally been flowing ever since."

A graduate student came up with the idea of recording the giggling rats by using "bat detectors," sophisticated instruments that register high-pitched sounds humans cannot hear.

"Lo and behold ... it sounded like a playground," Panksepp said, adding that keeping rats laughing isn't difficult.

"It's quite easy. They're small, of course, but it's really no different than running your fingers as if you're tickling a child," he said. "You get the most laughter at the nape of the neck, where they direct each other's play behavior."

Rats register their gratitude with little nips.

"I have literally tickled hundreds of rats," Panksepp said. "The amazing thing is, prior to starting this line of research, I had never been bitten by a rat. But since I've started this, I've been bitten hundreds, if not thousands, of times, but always in a playful way.

"The skin has never been broken. It's like a puppy dog biting you."

Panksepp knows people may laugh at his research, but he doesn't care since his goal is to track the biological origins of joy.

"We interpret this as a primitive, childlike joyfulness," he said. "Where do we humans get more laughter than anywhere else? On the playground, where kids are running and playing. It's the same with tickled rats."