" 't was heels up and head down"

One of Mirah's more charming books is Duck Song, a board book by Kenneth Grahame, pictures by Joung Un Kim [Update: I probably should have already known this, but I just noticed the fine print on the book informing us that the words earlier appeared in Grahame's classic The Wind in the Willows]. Here are the words:

All along the backwater,
Through the brushes tall,
Ducks are a-dabbling,

Up tails all!

Ducks' tails, drakes' tails,
Yellow feet a-quiver,
Yellow bills all out of sight
Busy in the river!

Slushy green undergrowth
Where the fish swim--
Here we keep our larder,
Cool and full and dim.

Everyone for what he likes!
We like to be
Heads down, tails up,
Dabbling free!

High in the blue above
Swifts whirl and call--
We are down a-dabbling

Up tails all!

It's one her recent favorites; we like to read it to her too. Then, just this morning, going through my excellent Christmas book haul, I found in the new NYRB edition of Thoreau's Journal (edited by Damion Searls) the entry from October 29, 1837:

Two ducks, of the summer or wood species, which were merrily dabbling in their favorite basin, struck up a retreat on my approach, and seemed disposed to take French leave, paddling off with swan-like majesty. They are first-rate swimmers, beating me at a round pace, and—what was to me a new trait in the duck character—dove every minute or two and swam several feet under water, in order to escape our attention. Just before immersion they seemed to give each other a significant nod, and then, as if by a common understanding, 't was heels up and head down in the shaking of a duck's wing. When they reappeared, it was amusing to observe with what a self-satisfied, darn-it-how-he-nicks-'em air they paddled off to repeat the experiment.