The Moons of Mars

From Galaxy Science Fiction September 1952 (An Excerpt) Every boy should be able to whistle, except, of course, Martians. But this one did! He seemed a very little boy to be carrying so large a butterfly net. He swung it in his chubby right fist as he walked, and at first glance you couldn't be sure if he were carrying it, or it carrying him. He came whistling. All little boys whistle. To little boys, whistling is as natural as breathing. However, there was something peculiar about this particular little boy's whistling. Or, rather, there were two things peculiar, but each was related to the other. The first was that he was a Martian little boy. You could be very sure of that, for Earth little boys have earlobes while Martian little boys do not--and he most certainly didn't.