The backyard looked as still as ever. A gentle breeze blew through the tall tree behind my house as a squirrel darted from one branch to the next. And the squawking continued.
I stared in the direction of the noise but was unable to identify the source at first. It took a minute or two for me to find the small brown-headed nuthatch hiding nearby still full of noise and excitement.
A little internet research tells me that the type of serial vocalization that this little guy (or girl) was engaged is given when birds are fairly close together, either during times of apparent excitement or normal foraging.
I'm going with excitement because if you were in the DC area today you'd know the cool, fall-like weather was something to squawk about.