Lecture, three hours; discussion, one hour. Enforced requisite: Life Sciences 7B. Comprising 20 percent of all mammals and inhabiting all but one continent, bats are the only mammals capable of powered flight. Bats can also echolocate, hibernate, live longer than humans, and harbor viruses but not get sick. This allows bats to be reservoirs for many viruses that can cause zoonotic diseases in humans, including Ebola and SARS-CoV-2, the virus that causes COVID-19. Exploration of evolution, anatomy, physiology, immunology, longevity, and conservation of bats. Focus on how scientists use bats as model system to address key questions in ecology, evolution, and human health. Letter grading.