This annual invasion reminds me of a poem by Bill Holm:

NUCLEAR PHYSICISTS USE ASTOUNDING
COMPARISONS TO MAKE CLEAR THE NATURE
OF INFINITE NUMBERS

An adult male Norwegian
weighs as much as 
two and a half billion
boxelder bugs. 
Is it any surprise that
there are more boxelder bugs
than Norwegians?
Imagine a planet in which
Norwegians crawled up
and down your kitchen walls
by the thousands, hid
under the warm coffee pot, 
fell like discolored noodles out
of the noodle bags where they slept; 
after the blizzards started, 
you would find Norwegians
dried inside light fixtures, Norwegians
clogging up the vacuum cleaner, 
Norwegians floating in
cups of lukewarm coffee.