In the animal world, if you take rats, who are hardwired to play at a certain period of their juvenile years and you suppress play -- they squeak, they wrestle, they pin each other, that's part of their play.
U životinjskom svijetu,  ako uzmete štakore, koji se kao mladunci instinktivno igraju, i ne dozvolite im igru  -- oni ciče, hrvaju se, ruše jedni druge, to je dio njihove igre.