Many people are unaware of how intelligent pigeons are. They may be taught to recognize words and to match art with its artist, but perhaps most importantly, they can be taught to distinguish between benign and cancerous growths. Researchers at the University of California, Davis, trained pigeons to distinguish between benign and malignant biopsies. The pigeons were able to "diagnose" brand new biopsies that they had never seen before after being trained how to differentiate between the two. A pigeon by itself had an accuracy of 85% on average. Their accuracy as a group approached 99%, which is expected of a doctor.