Bacteria are invisible to the naked eye, but they reside on nearly every surface humans encounter -- including the skin. Uncovering the role these microorganisms play in human health is a major focus of research in skin microbiology, but little is known about the identity or function of skin bacteria in other mammals. Researchers have now identified a core skin bacterial community that humpback whales share across populations, which could point to a way to assess the overall health of these endangered marine mammals....