Desert

* Deserts are characterized by less than ten inches of precipitation per year and hot temperatures. * Some deserts are hot during the day and freezing cold during the night. * Much of Antarctica is considered a desert, as very little NEW snow falls. * Deserts cover about 20 percent of the Earth's surface. In some of the world's most arid deserts, rain has not fallen in years or even decades. * Many animals that live in the desert are nocturnal and become active when temperatures fall. * Some desert animals have incredible adaptations to help them survive in the desert. Species such as the Fennec Fox or Desert Hare have huge ears to help them release excess heat. * The Sonoran Desert in North America is home to the Saguaro Cactus, the world's tallest cactus. These cacti can live 150 years and grow to sixty feet in height.   Click on a biome to learn more