in Thoreau’s Journal:

Six weeks ago I noticed the advent of chickadees and their winter habits. As you walk along a woodside, a restless little flock of them, whose notes you hear at a distance, will seem to say, “Oh, there he goes, let’s pay our respects to him!”

and they will flit after and close to you and naively peck at the nearest twig to you, as if they were minding their own business all the while, without any reference to you.