Loren Eiseley (1907-1977), The Immense Journey
(New York: Vintage Books, 1959), p. 25:
Every spring in the wet meadows and ditches I hear a little shrilling chorus which sounds for all the world like an endlessly reiterated "We're here, we're here, we're here." And so they are, as frogs, of course. Confident little fellows. I suspect that to some greater ear than ours, man's optimistic pronouncements about his role and destiny may make a similar little ringing sound that travels a small way out into the night. It is only its nearness that is offensive. From the heights of a mountain, or a marsh at evening, it blends, not too badly, with all the other sleepy voices that, in croaks or chirrups, are saying the same thing.