any of 36 nocturnal species of small rodents found from the United States southward through tropical and portions of subtropical South America. Rice rats have soft fur, with tawny to grayish brown upperparts and paler underparts. Their tails are sparsely haired and vary in length depending upon the species. Body size also varies. Among the smallest is Oryzomys alfaroi, from southern Mexico to western Ecuador, with a body up to 12 cm (4.7 inches) long and a slightly shorter tail; among the largest is O. angouya, found in eastern Brazil, Paraguay, and southern Argentina, with a body length up to 20 cm and a much longer tail
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