The round-tailed ground squirrel, known as "Ardillón cola redonda" in Spanish, live in the desert of the Southwestern United States and Northwestern Mexico. They are called "ground squirrels" because they burrow in loose soil, often under mesquite trees and creosote bushes.

Round-tailed ground squirrels are adorable tiny creatures. A newborn squirrel weights around 3.9 grams (0.14 oz). Adults weigh approximately 125 grams (4.4 oz). They have hairy and strong hind feet and a long tail. The underside of the body is usually lighter than the rest of it. Round tailed squirrels average 204 to 278 millimetres (8.0 to 10.9 in) in length including the tail which is from 60 to 112 millimetres (2.4 to 4.4 in) long. They live for approximately 9 years, but there is no exact information in this respect.

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