# Hispid Cotton Rat (Sigmodon hispidus) - Web page: https://www.funwildfacts.com/nordamerika/mammal/hispid-cotton-rat - Published: 2026-05-30 - Last updated: 2026-05-30 ## Overview The hispid cotton rat (Sigmodon hispidus) is a medium-sized rodent named for its coarse, grizzled fur that feels almost bristle-like to the touch. This robust animal belongs to the family Cricetidae and is one of the most common rats in the southern United States, Central America, and northern South America. The body is stocky and compact, with a relatively short tail measuring only about half the length of the body. The fur varies from grayish-brown to blackish-brown on the upper parts, while the belly is lighter, often grayish-white or yellowish. This rat is remarkably productive and can reproduce year-round in warmer climates. Females can produce up to nine litters per year, with 1-15 young per litter, though the average is 5-7. The young are born blind and hairless but grow very rapidly and can reproduce themselves at just 6-8 weeks of age. This extreme reproductive capability means that populations can explode under favorable conditions, making the hispid cotton rat one of the most prolific mammals in its range. The hispid cotton rat plays an important ecological role as both prey animal and herbivore. It feeds primarily on grasses, grains, seeds, and roots, but also takes insects and snails when available. The animal creates well-worn runways through dense vegetation, and builds spherical nests of grass either on the ground or in shallow underground tunnel systems. These runways and nests often become visible in fields and grasslands where cotton rats are numerous. Despite its small size, the hispid cotton rat is of great scientific interest because it is widely used in medical research, particularly for studying infectious diseases. The animal is naturally susceptible to many diseases that affect humans, making it a valuable model organism. In nature, snakes, owls, hawks, foxes, and many other predators actively hunt the hispid cotton rat, which forms an important part of the food chain. ## Quick facts - Weight: 50–225 g - Length: 19–36 cm - Lifespan: 0.5–1.5 yrs - Diet: Herbivore - Conservation Status: Least Concern ## Habitat The hispid cotton rat thrives in areas with dense ground vegetation that offers both food and cover. It prefers grasslands, fields with tall grass, marshes, wetlands, and the edges of agricultural land. It is especially common in old fields where grass and weeds have grown thick, providing perfect cover from birds of prey and other enemies. The animal is also common in abandoned cotton fields, corn fields, and along roadsides where vegetation is lush. In areas with suitable habitat, cotton rats can reach high densities, sometimes up to 200 individuals per hectare during favorable years. They build their nests either above ground in dense grass clumps or in shallow tunnel systems a few centimeters below the surface. The hispid cotton rat is adaptable and has also colonized urban areas such as parks and gardens, especially where there is access to coarser vegetation and food waste. - Grassland - Farmland - Wetland - Woodland - Garden - Urban ## Seasonal Behavior In the southern parts of its range, the hispid cotton rat is active and reproduces year-round, without any true winter dormancy. In more northern areas, activity decreases somewhat during winter, but the animals do not hibernate. Instead, they gather stores of seeds and plant material in their nests and remain active even under snow. Populations vary greatly between seasons, with the highest numbers in late summer and fall after several months of reproduction. Winter and drought can decimate populations severely, but they recover quickly when conditions improve. ## Breeding - Gestation: 27 days - Offspring: 1–15 ## Behavior & Ecology - Activity Pattern: Nocturnal - Social Behavior: Lives in loosely organized colonies where several individuals share the same area and sometimes the same tunnel system, but each individual is territorial around its own nest. - Migration: Resident - Population: Very common with large, stable populations throughout its range ## Did you know? - The hispid cotton rat's fur is so coarse it feels almost like bristles – hence its scientific name 'hispidus' meaning 'bristly'! - A single female can theoretically produce over 100 offspring in one year, making it one of the most productive mammals in North America. - Cotton rats create distinct 'highways' through grass – well-worn runways that can be seen from above and which they use to quickly flee from enemies. - Despite its name, the cotton rat rarely eats cotton – the name comes from it often being found in cotton fields where it feeds on seeds and insects. - This rat is a good swimmer and often crosses waterways to find new feeding areas or escape predators. - Cotton rats stomp their hind feet to warn each other of danger, creating a drumming sound in their tunnel systems. - They can eat more than half their own body weight in food each day – equivalent to a human eating about 88 pounds of food daily! - The young grow so rapidly that they weigh ten times more at three weeks of age than they did when born. ## Taxonomy - Kingdom: Animalia - Class: Mammalia - Order: Rodentia - Family: Cricetidae - Species: Sigmodon hispidus ## Image - URL: https://images.djurfakta.com/animals/bomullsratta/1777968896112-1.jpg - Photo: ALAN SCHMIERER - License: CC0 ## Other languages - sv: https://www.djurfakta.com/nordamerika/mammal/bomullsratta - da: https://www.dyrefakta.com/da/nordamerika/mammal/bomulds-bomuldratte - no: https://www.dyrefakta.com/nordamerika/mammal/bomullsrotte