 Why is the narrator the only one who notices a flight of volplas soaring slowly across the full Moon?
Volpla By WYMAN GUIN Illustrated by [Transcriber's Note: This etext was produced from Galaxy Science Fiction May 1956. Volplas at last. Yet I had always been so sure I could create them that I had been calling them volplas for ten years. I had called them volplas since the day old Nijinsky's elongated arms and his cousin's lateral skin folds had given me the idea of a flying mutant. When Nijinsky saw me looking at him, he started a little tarantella about his cage. I smiled with nostalgia when the fifth fingers of his hands, four times as long as the others, uncurled as he spun about the cage. She skated awkwardly between the rows of cages from which mutants with brown fur and blue fur, too much and too little fur, enormously long and ridiculously short arms, stared at her with simian, canine or rodent faces. Again in the laboratory, I entered the metabolic accelerator and withdrew the intravenous needles from my first volplas. The accelerator had forced them almost to adulthood in less than a month. It would be several hours before they would begin to move, to learn to feed and play, perhaps to learn to fly. Meanwhile, it was clear that here was no war of dominant mutations. I thought, "All this and three volplas, too." I wiped the back of my hand across my mouth and said aloud, "Yes, sir, the dangerous age. I kissed her until I heard rollerskates coming across the terrace from one direction and a horse galloping toward the terrace from the other direction. I've only had the feeling once before in a small way, but I've always...." Outside this little town, I found a litter of flat stones that had young black-snakes under each slab. I filled a pail with them and took them into town and dumped them on the walk in front of the movie just as Theda Bara's matinee let out. I had aimed only at a gliding mammal a little more efficient than the Dusky Glider of Australia, a marsupial. Except for the face, chest and belly, they were covered with a soft, almost golden down. The spars had been common to the basic colony for years and were the result of serial mutations effecting those greatly elongated fifth fingers that had first appeared in Nijinsky. No longer jointed like a finger, the spar turned backward sharply and ran alongside the wrist almost to the elbow. Powerful wrist muscles could snap it outward and forward. Suddenly, as I teased the male volpla, this happened.
 Because people generally only notice what they look for and would dismiss the phenomenon as something else.
 Because volplas are fictional creatures and people do not believe they exist.  Because other witness believe this was ET with  a little boy riding his bicycle over the moon.  Because people generally only notice what they look for and would dismiss the phenomenon as something else.  Because it is nighttime and everyone is indoors.