Why do fireflies have to die so soon?

Mature fireflies which emit light have extremely short life spans of two to three weeks and are traditionally regarded as a symbol of impermanence, which resonates with much of classical Japanese tradition (as with cherry blossoms). Fireflies are also symbolic of the human soul (“Hitodama”), which is depicted as a floating, flickering fireball. Heikebotaru (平家蛍,…