When the mayflies emerge it is in great numbers
from lakes where they have lived in nymphal skins
through many molts. At the last
a downy skin is shed and what proofed them
is gone. Above water there is
nothing for them to feed on—

they don’t even look, except for each other.

They form hurried swarms in that starving, sudden hour
and mate fully. When it is finished it is said
the expiring flies gather beneath boatlights
or lampposts and die under them minutely,
drifting down in a flock called snowfall.