White nose syndrome is an illness that weakens and kills bats roosting in caves. Affected animals have a white fungus around their muzzle and on their wings, but no one knows if the fungus causes the illness or simply infects bats that are weakened by some other disease. Search the Internet for the latest information about white nose syndrome; then propose a testable hypothesis to explain how the fungus might have entered bat populations. What information would you need to determine whether the fungus actually causes the disease? How can people help prevent the spread of the fungus from cave to cave? If the disease continues to spread, how might the widespread death of bats affect ecosystems?