Their name derives from their damaging effects on cotton as well as other plantation crops, such as sugarcane, corn, peanut and rice.

[2][3] 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 United States, Mexico, Central America, and South American countries of: Venezuela, Ecuador, Colombia, Peru, Brazil, Guyana, and Suriname.

The molars of cotton rats are S-shaped when viewed from above.

Sigmodon hispidus was the first model organism to be used in polio research.