Life in the Deserts, by Lucy Baker. New York: Scholastic, 1990.
Deserts are areas that have less than 25.4 cm (10 in) of rainfall per year, with daytime temperatures reaching 55° C (131° F) and above during the day, and near freezing at night.. Most of our deserts lie along the equator, including the largest, the Sahara desert. In such regions, the evaporation rate exceeds the precipitation rate, because of the low humidity of the atmosphere.
Because of this extreme environment, plants and animals of the deserts have evolved adaptation that allow them conserve water to astonishing degrees.