Drs. Elaine Beaulieu and Michael Country speak with Dr. Dillon Chung, a physiologist who focuses on the mitochondria of different animals. He's a comparative physiologist, which means he learns physiology by learning from a range of animals, letting them teach him their secrets. He's studied metabolism at the extremes: he's looked at hibernating 13-lined ground squirrels, which by some measures can drop their metabolism by 95-99%. On the other end of the spectrum, he's currently working on shrews - tiny mammals with metabolisms so high that some species may consume double their bodyweight in food every day. He especially focuses on mitochondria, and he currently works in a mitochondrial lab in the National Institutes of Health.