"A team of German neuroscientists from the Humboldt University of Berlin spent several weeks hanging out with rodents in a small room filled with boxes. They were playing human-vs-rodent hide-and-seek and found out the animals were surprisingly adept at the cross-cultural childhood game. They weren’t even given treats as a reward, rather, they were given attention in the form of friendly petting and tickles.
The rats were having so much fun they actually jumped for joy and laughed – ultrasonic inaudible giggles to be precise. They were truly enjoying the fun of both finding their sneaky human companions and being caught by them. Although, if you ever end up playing with a rodent yourself and he giggles, you won’t hear it. Their mischievous giggles have to be picked up by scientific equipment because they’re too high-pitched to be detected by the human ear. The study has been published in the journal Science."
https://www.intelligentliving.co/amp/rats-play-hide-and-seek-giggled-jumped/
Science 13 Sep 2019:
Vol. 365, Issue 6458, pp. 1180-1183
DOI: 10.1126/science.aax4705
The rats were having so much fun they actually jumped for joy and laughed – ultrasonic inaudible giggles to be precise. They were truly enjoying the fun of both finding their sneaky human companions and being caught by them. Although, if you ever end up playing with a rodent yourself and he giggles, you won’t hear it. Their mischievous giggles have to be picked up by scientific equipment because they’re too high-pitched to be detected by the human ear. The study has been published in the journal Science."
https://www.intelligentliving.co/amp/rats-play-hide-and-seek-giggled-jumped/
Science 13 Sep 2019:
Vol. 365, Issue 6458, pp. 1180-1183
DOI: 10.1126/science.aax4705