[music playing]
NARRATOR: Something is
stirring at the bottom
of the Mississippi River.
A mayfly larva, one of
millions, erupts out of the mud.
On low-lying foliage, they
shed their larval shells.
This will be the most
important day, the only day,
of their adult lives.
They have just 24 hours to
take to the air, find a mate,
breed, and die.
The cloud of breeding,
dying mayflies
is so dense that it can be
picked up on weather radar.
Mississippi fauna indulges
in the yearly feast.
The majority of the mayflies
will survive to breed, shedding
their spawn into the river.
Next year, the eggs will hatch
for another day of breeding,
feasting, and death.
