Rats Laugh When Tickled

A YouTube gem from 2007 is making the rounds again, teaching us something kind of neat and kind of gross: Rats laugh when tickled. When a Bowling Green University professor decided to try tickling the rodents, and then listening to their resulting high-frequency noises on a “bat detector,” he discovered that the rats not only laughed—they actually seemed to be enjoying the whole activity, New York reports.
(More rats stories.)