Organ Pipe Wasp Nests

Minding my own business at the computer yesterday, the sound of pecking outside the window was enough motivation to go out in the cold to see who, or what, was trying to take the siding off the house.  Slowly approaching the pecking sound, now identified as coming from the underside of the deck above the window, something fell down and bounced on the patio, and then a downy woodpecker flew out.  The photo above shows one of the several organ pipe mud dauber wasp nests constructed under the deck.  You can see the damage the woodpecker has done (to the nests), probably looking for larvae or spiders that the wasps left last fall.  Mud dauber wasps tend to be nice to have around, they are not aggressive, eat lots of spiders, and are, in turn, eaten by birds - I've watched bluebirds take wasps on the wing.