A Japanese zoo unsuccessfully tried to mate a pair of hyenas… A Japanese zoo unsuccessfully tried to mate a pair of hyenas for four years before realizing both were males.Source: Unbelievable Facts Interesting Facts Related posts:unbelievable-facts:Dolphins have “bromances” in which two males… Japanese shoemaker Kyoto Ohata has created a hilarious pair of… Female spotted hyenas get giant erections. They’re often… Nerdy Fact #1621: Warner Bros. unsuccessfully sought after Oprah…