(..) Brecht’s team even taught the rodents to play hide and seek. At the beginning of the game, a rat was enclosed in a box while a researcher hid somewhere in the room. The researcher then opened the box using a remote control, allowing the animal to jump out and begin “seeking.” When the rat successfully found the hidden scientist, it was rewarded with—you guessed it—a tickle. The rats were also given the opportunity to hide while the researchers looked for them, and they proved to be especially good at coming up with creative hiding spots. Their ability to strategize was “almost spooky,” Brecht recalls.
(...) Brecht’s team first made sure the rats were comfortable with their new playground, aka a dimly lit plastic box, as well as their human playmates. The researchers then played games of “chase the hand” and tickled and the animals on their backs and bellies (see video (...) for an example from a previous experiment). In response to the tickling, the rats shimmied in delight and let out endless “giggles.”
Almost every part of the article was as entertaining as it was interesting, haha! Not only did they spend months tickling rats, but they actually turned up some new information on how the brain works in the process.
I'll bet they wrote that proposal expecting to be rejected for any kind of grant and then were laughing all the way to the laboratory after hearing it was granted.
“The research that does exist shows rats will keep playing even after their entire cortex, the part of the brain essential for consciousness and higher level behaviors, has been destroyed. “