During winter, the Eskimos live in igloos. An igloo is a traditional shelter made of blocks of snow or ice that are stacked in a circular pattern to form a dome-shaped structure. The snow and ice act as excellent insulators, keeping the inside of the igloo relatively warm and protecting the occupants from the cold and wind outside. Igloos are designed to be relatively small and are easy to construct using simple tools, making them a practical and effective shelter for the harsh Arctic winter. While Eskimos may also use other forms of shelter, such as tents or caves, igloos are a well-known and iconic example of traditional Eskimo housing. Therefore, the correct answer is igloos.