Dive-bombing hawks send posties running

Not snow, nor rain,
nor hail, nor sleet...

Or barking dogs or aching feet,

Or crazy kids or funny hats,
or packages and heavy sacks

Nor great windy twisters
that drop in from Kansas
Nor bamboo forests
with black-and-white pandas

Nor iron gates or garbage cans
or blistering, barren destert lands

Nor wolves that howl with all their might,
nor spooky shadows in the night

Nor chocolate cake or cinnamon,
Nor baking soda or fishes' fins

Nor copper pennies on the ground,
nor pirate treasure to be found,

Nor rabbit holes or grandfather clocks,
nor rivers rushing over rocks

Nor silver dollars or paper money
Nor shooting stars or the Sunday funnies

Nor thumbtacks or armor,
Nor an expert snake-charmer

Nor swinging bridges
for boats to go through,
Nor her or him or me or you...

Can stop us from delivering the mail,
every day, and without fail.

"raydan" said

...on a side note, I remember at one place I lived getting attacked by swallows at a certain time of the year.