He had coaxed an exquisite blue caterpillar to climb aboard a twig. It briskly padded along, its iridescent body rippling with the motion of fourteen pairs of feet. At the end of the twig, it held on with its last five [sic] segments and flailed the air in a plucky attempt to find a new perch. Unsuccessful, it turned itself around smartly and retraced its many steps. Der Heer then changed his clutch on the twig so that when the caterpillar returned to its starting point, there was again nowhere to go. Like some caged mammalian carnivore, it paced back and forth many times, but in the last few passages, it seemed to her, with increasing resignation. She was beginning to feel pity for the poor creature, even if he proved to be, say, the larva responsible for the barley blight.

"What a wonderful program in this little guy's head!" he exclaimed. "It works every time--optimum escape software. And he knows not to fall off. I mean the twig is effectively suspended in air. The caterpillar never experiences that in nature, because the twig is always connected to something. Ellie, did you ever wonder what that program would feel like if it was in your head? I mean, would it just seem obvious to you what you had to do when you came to the end of the twig? Would you have the impression you were thinking it through? Would you wonder how you knew to shake your front ten feet in the air but hold on tight with the other eighteen?"