Answers: Mystery of the Cosmati year Hedgehogs live for 3 years (times this by 3 to get your next answer) Dogs live for 9 years (keep multiplying by 3) Horses live for 27 years Man lives for 81 years Stags live for 243 years Ravens live for 729 years Eagles live for 2,187 years Whales live for 6,561 years The World ...