Classicly

Gordy fed the man, and accepted a cigarette from him after they had eaten. The first puffs made him light-headed—it had been that long since he'd smoked—and through the smoke he looked at John de Terry amiably enough. Company would be all right, he thought. The pink mice had been company, of a sort—but it turned out that the mutation that made them hairless had also given them an appetite for meat. And after the morning when he had awakened to find tiny tooth-marks in his leg, he'd had to destroy them. And there had been no other animal since, nothing but the ants.