Cottontail rabbits comprise the genus Sylvilagus, which is in the family Leporidae. They are found in the Americas. Most Sylvilagus species have stub tails with white undersides that show when they retreat, giving them their characteristic name, but this feature is not present in all Sylvilagus species, nor is it unique to the genus. Their fur ranges from brown to gray and changes throughout the year, depending on the season.