Fists up, brains up! This week, we're heading into the ring filled with facts and trivia about fighting: learn about the (nice) Japanese tradition of spider fighting, and find out why MMA fighters should not blow their noses. Colin finds out what exactly did occur and spur, sir, during that fateful duel between Alexander Hamilton and Aaron Burr. Everyone was kung-fu fighting in Karen's Asian martial arts quiz, and just how well do you know your professional wrestler movie cameos? ALSO: beaver teeth, eyeball transplant Learn more about your ad choices. Visit megaphone.fm/adchoices