Empathy and compassion have long been considered exclusive human traits and some of the loftiest of religious values. But an experiment at the University of Chicago has demonstrated that even rats can show empathy and altruism toward their comrades. Strange rats, unrelated to each other, were put together in a cage. After two weeks some of the rats were placed in a very small cell within larger cages. In a week's time three-fourths of the free rats learned how to free the caged rats. And one half of the free rats would save one or two chocolate chips for the trapped rats, demonstrating both empathy and altruism ("Science on religion," Patheos, March 9).