I bought the Tornado Game for our two Basenjis to test their mental skills.
http://www.doggietshirts.com/Nina-Ottosson-Plastic-Dog-Games
Dog - A is a female, Dog - B is a male.
Dog A figured out how to remove the bones & twist the levels to get to the treats. Dog B stood & watched as Dog A removed the bones, then ate the revealed snacks while Dog A put the bones on a pillow some distance away.
Which dog is smarter, Dog A who figured out the puzzle, or Dog B for not even trying, but waiting to steal the treats?