BERLIN — Humans aren’t the only species capable of enjoying some fun and games. A team of researchers from Humboldt University in Berlin, Germany successfully taught a group of lab rats how to play hide-and-seek, and over time the rats even developed strategies for both hiding and seeking.
Furthermore, scientists observed the rats openly expressing joy and happiness whenever they evaded detection or successfully found their target.
Animals of all kinds are known to play among each other, but there really hasn’t been much research into the behavior from a neurological perspective. This is mostly due to the fact that animal play is a “free” activity that doesn’t offer any concrete benefits besides the game itself, making it difficult for neuroscientists to apply traditional conditioning and strict controls in an experimental setting. So, it is still very much a mystery what exactly goes on, at a neural level, in animals’ heads as the play.
In an effort to gather more data on this understudied topic, head researcher Annika Reinhold and her colleagues taught a group lab rats how to play a simplified version of human vs. rat hide-and-seek. Remarkably, after just a few weeks the rats knew how to play the game at a “highly proficient” level, and even knew when and how to switch between hiding and seeking roles.
While seeking, the rats learned to look for hiding humans and to keep looking until they found someone. While hiding, the rats knew to stay in one concealed place until being discovered by a human.
After playing, the rats were rewarded for successfully playing hide-and-seek, but not with food. Instead, rats were given congratulatory playful social interactions, such as petting, tickling, or playful fighting.
“They chase our hand, we tickle them from the side, it’s like a back and forth a little bit like how you play with small kittens or puppies,” explains co-researcher Konstantin Hartmann in an AFP interview.
Perhaps the most interesting finding of all was that the rats seemed to become more strategic with their in-game movements as time went on. As the rodents become experienced hide and seek players, they began systematically searching areas, responding to visual cues, and even knew to check spots where they had discovered humans in the past. Conversely, as rats became more experienced at hiding they learned to stay completely still and silent, and picked up on the fact that they should hide behind cardboard boxes instead of transparent boxes.
The research team also noted that the rats genuinely seemed to enjoy playing hide-and-seek. In fact, after successfully finding a human or evading detection, the rats would often let out a joyful squeak or jump. Even during the course of a game some rats were known to let out high-pitched giggles and “joy jumps.” Often times, after being caught by a human, the rats would jump away and “playfully re-hide” — a sign that the animals enjoyed playing so much they didn’t want to stop.
“When you work a lot with rats over the years, you see how intelligent these animals are, and how social,” Hartmann comments.
Researchers also observed significantly elevated activity in the rats’ prefrontal cortexes, that varied and changed depending on how the game was going and the role they were playing.
The study is published in the journal Science.