Cotton rat
A cotton rat is any member of the rodent genus Sigmodon. Cotton rats have small ears and dark coats, and are found in North and South America. Members of this genus are distributed in the Southwestern USA, Mexico, Central America and South American countries of: Venezuela, Ecuador, Colombia, Peru, Brazil, Guyana and Suriname. Many of the species are found in Mexico.
They are primarily herbivores. The molars of cotton rats are S-shaped when viewed from above. The genus name literally means S-tooth.
Sigmodon hispidus was the first model organism to be used in polio research.Classification
