Australian scientists recently reported that octopuses were the first invertebrates to be observed using tools. In January, in a laboratory, a crow became the first bird to show "insight" -- grasping the solution to a problem by mental activity, not trial-and-error behavior. Today virtually all animal scientists agree that animals -- down through the insect kingdom -- have amazing powers of mind. Nevertheless, some scholars warn against concluding that animals' minds are like the minds of humans. Skeptics say there is no evidence animals can generate language in the creative way humans can or form abstract concepts of things they cannot see or touch. A case in point, say some, is the fall from grace of Marc Hauser, a leading animal-mind researcher who championed an expansive view of some animals' mental abilities. Hauser was placed on leave from his Harvard professorship in August after a university probe concluded that he had falsified data in several of his high-profile studies.

Marcia Clemmitt is a veteran social-policy reporter who joined CQ Researcher after serving as editor in chief of Medicine and Health, a Washington-based industry newsletter, and staff writer for The Scientist. She has also been a high school math and physics teacher. She holds a bachelor's degree in arts and sciences from St. Johns College, Annapolis, and a masters degree in English from Georgetown University.