Deserts represent one-fifth (20%) of the land surface of the world.
The majority of deserts are in the Arabian Peninsula, Australia, The Americas, North and South Africa, India and Pakistan.
The largest desert is the Sahara, in North Africa, and is about 3,500,000 square miles.
Deserts are characterized by extreme heat and dryness, very hot in the daytime and chilly or even cold at night.
The average temperature is 100 degrees during the day and below 50 degrees at night.
The wettest desert does not get more than 10 inches of rain a year.
A variety of plant and animal species live there, thanks to their power to adapt to the harsh environment. Camels, for example, are able to store large quantities of water in their humps.
Animals like rattlesnakes and scorpions spend most of the day underground but come out at night to eat and hunt.
Spade foot toads spend 9 months of the year underground.
Deserts often get their names like "Death Valley" or "The place from where there is no return" because of their extreme conditions.
