A new disease is causing strange behavior in young black bears in California and Nevada. Videos and other reports have appeared around Lake Tahoe and in California documenting young bears having no qualms about getting close to humans. One video even shows a black bear (Ursus americanus) scrambling over a man’s snowboard. Scientists have discovered five new viruses in bears with these symptoms, some of which are inflicted with encephalitis. Other symptoms include a slightly tilted head and head tremors, and many bears with inflamed brains are also underweight. Wildlife managers have had to euthanize the bears due to their weak condition. They are still trying to learn more about the unknown disease.