The evidence collected to date indicates that human activity in caves and mines may be assisting the spread of WNS. The primary agent of concern is a fungus that is new to science and may possibly be an invasive species. This fungus grows best in the cold and wet conditions common to caves and abandoned mines and likely can be transported inadvertently from site-to-site on boots and gear of cave visitors. Therefore, the U.S. Fish and Wildlife Service is recommending actions to reduce the risks of further spread of WNS. We hope that slowing the spread of WNS will buy time that is critical to confirming the cause and potentially implementing management actions to minimize the impacts to native bat populations.