Cotton rats are found mainly in the southwestern and southeastern U.S. These rodents are so named because of their propensity to build their nests out of cotton, as well as eat the crop.
Cotton rats are fairly large, stocky rats, with short ears and a short tail. Their coat is a gray black mix, similar to a salt-and-pepper coloring. These rodents also have a unique tooth pattern. Their molars are S-shaped, and that trait is responsible for their genus name, Sigmodon hispidus, which means “S tooth”.
Cotton rats build their nests in grassy areas or piles of brush. They usually prefer to live near cultivated fields, where they gather the majority of their food supply. Cotton rats will rarely invade a home, and prefer to live outdoors. They eat a diet of primarily plants and herbs. These rats are also dynamic breeders. Cotton rats can experience population explosions when the conditions are right. Females will produce litters 9 times a year. These litters usually consist of 5 young. Females can breed immediately after the litters are born, with the young mice reaching sexual maturity in 40 days.
Cotton rats are nocturnal feeders, primarily herbivores, but they also will eat eggs from ground nesting birds, such as quail, as well as insects and dead animals. Cotton rats can devastate agricultural crops in large numbers. Harvests of watermelon, peas, sugarcane, beans and, of course, cotton can be severely depleted by these pests. However, cotton rats have a large number of natural predators, which manage to keep their populations at low numbers most of the time. Cotton rats also have extremely short life spans, averaging up to 6 months.
Managing cotton rats can be difficult. Keep brushy areas cut down that surround fields. Also, use traps and baits, which are specifically designed for cotton rats and the crops they eat.