"The landing was in the winter time," he observed. "It must have been, because the colony survived a while. And at a guess, the last ship-landing was before thaw. The years are eighteen months long here, you know." "It was in winter that the landing was made," Bordman admitted. "And the last ship-landing was before spring. The idea was to get mines in operation for material, and to have ground cleared and enclosed in sphex-proof fence before the sphexes came back from the tropics. They winter there, I understand." "Did you ever see a sphex?" asked Huyghens. Then he said, "No, of course not. But if you took a spitting cobra and crossed it with a wild-cat, painted it tan-and-blue and then gave it hydrophobia and homicidal mania at once, you might have one sphex. But not the race of sphexes. They can climb trees, by the way. A fence wouldn't stop them." "An electrified fence," said Bordman. "Nothing could climb that!" "Not one animal," Huyghens told him. "But sphexes are a race. The smell of one dead sphex brings others running with blood in their eyes. Leave a dead sphex alone for six hours and you've got them around by dozens. Two days and there are hundreds. Longer, and you've got thousands of them! They gather to caterwaul over their dead pal and hunt for whoever or whatever killed him." He returned to his meal. A moment later he said: "No need to wonder what happened to your colony. During the winter the robots burned out a clearing and put up an electrified fence according to the book. Come spring, the sphexes come back. They're curious, among their other madnesses. A sphex would try to climb the fence just to see what was behind it. He'd be electrocuted. His carcass would bring others, raging because a sphex was dead. Some of them would try to climb the fence, and die. And their corpses would bring others. Presently the fence would break down from the bodies hanging on it, or a bridge of dead beasts' carcasses would be built across it--and from as far down-wind as the scent carried there'd be loping, raging, scent-crazed sphexes racing to the spot. They'd pour into the clearing through or over the fence, squalling and screeching for something to kill, I think they'd find it." Bordman ceased to eat. He looked sick. "There were pictures of sphexes in the data I read. I suppose that would account for--everything." He tried to lift his fork. He put it down again. "I can't eat," he said abruptly. Huyghens made no comment. He finished his own meal, scowling. He rose and put the plates into the top of the cleaner. "Let me see those reports, eh?" he asked dourly. "I'd like to see what sort of a set-up they had, those robots."