Cotton Mouse

Scientific Name
Peromyscus gossypinus
Also Known As
Cotton Deer Mouse
All of Florida Except the Keys
Plants and Insects
Life Expectancy
1 Year
Florida Cotton Mouse

Photo 180709664 (c) Isaac Lord, CC BY-NC

Cotton Mouse conservation status - Least Concern

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Cotton Mice in Central Florida

The cotton mouse (Peromyscus gossypinus) is a small rodent native to the southeastern United States, including central Florida.

Often confused with the white-footed mouse, cotton mice can be identified by their larger size, grayish-brown fur, and habitat preferences. This guide provides identification tips, biology facts, and prevention methods for cotton mice inhabiting urban and suburban areas of central Florida.

Appearance and Identification

Cotton mice can be distinguished from similar Peromyscus species by examining both juvenile and adult physical characteristics

Adult Cotton Mouse

Photo 21362064 (c) Joshua Doby, CC BY-NC

Adult Cotton Mice

  • Size: Adults reach 17-20 cm long including the tail and weigh 35-50 grams. Their bodies alone are 8-10 cm long.
  • Tail: The tail is slightly furred, about as long as the head and body combined in adults.
  • Fur: The upperparts are brownish-gray mixed with tawny and black hairs. The underparts are pale gray. The fur is moderately long and soft.
  • Head: Rounded muzzle, prominent black eyes, and moderately sized ears.
  • Feet: Small feet with thin toes and tiny claws adapted for climbing and gripping.
Juvenile Cotton Mouse

Juvenile Cotton Mice

  • Size: Newborns weigh around 2-3 grams. They reach up to 30 grams in weight and 7 centimeters long at 5-6 weeks old.
  • Fur: Juvenile cotton mice have grayish fuzzy fur over their entire body, including the tail. The fur is short and soft as they grow.
  • Features: Younger mice have larger heads, feet, and ears proportional to their smaller body size. The tail is about as long as the body and head combined.

Cotton mice are larger with more tawny fur compared to white-footed mice. Their feet and tail lack the stark white underside of white-footed mice. Runways through vegetation, nests, tracks, and gnaw marks help identify cotton mice infestations.

Maturation Rate

Young cotton mice grow rapidly, reaching reproductive maturity by 6 weeks old. They are independent after weaning around 21 days of age. The average lifespan is about 1 year in the wild. Their high reproductive rate allows cotton mice to quickly rebound after control efforts.

Habits and Behavior

Cotton mice are nocturnal and most active during dawn and dusk hours. They prefers fields, scrublands, and wetland edges with dense grassy vegetation or brushy shrubs. Inside structures, cotton mice tend to occupy lower areas like basements and crawlspaces.

Outdoors, they construct globular nests made of shredded plant matter on the ground or low in bushes. Cotton mice can access homes through small openings around foundations. They are more solitary and territorial than house mice.

Reproduction and Lifespan

Cotton mice can breed year-round in central Florida. Females produce 2-3 litters per year with 1-7 young per litter. The gestation period is 23 days. Females may nest together when raising litters.

Ideal Habitat and Range

The warm, humid climate of central Florida provides ideal habitat for cotton mice. Average temperatures range from 60s to 70s°F in winter and 70s to 90s°F in summer. Rainfall is plentiful, especially June through September.

These conditions allow development of ideal cotton mouse habitat like tall grasslands, shrublands, forest edges, and wetlands. Rural pastures, citrus groves, and suburban yards surrounded by natural areas provide food, vegetation, and access to homes. Cotton mice flourish and numbers climb rapidly during warm, wet periods.

Diet and Feeding

Cotton mice are omnivorous and eat a varied mixture of plant and animal matter. Their diet includes:

  • Seeds and grains – wheat, oats, rye, berries
  • Fungi – mushrooms, truffles
  • Fruits – grapes, apples, citrus
  • Nuts – acorns, hickory, pecans
  • Green vegetation – grasses, leaves, stems
  • Insects – beetles, caterpillars, wasps, ants
  • Arachnids – spiders, ticks
  • Snails and worms

Cotton mice forage primarily on the ground but will climb for fruits and seeds. They frequently cache excess food in shallow holes or burrows. Home infestations result from cotton mice accessing stored grains, pet food, and edible waste.

The Exsudoporus floridanus such as this is the preferred food for the Florida Cotton Mouse
The florida cattail such as this is the preferred food for the florida Round-tailed Muskrat

Common Health Risks

Cotton mice can transmit diseases through direct contact, fleas, ticks, feces, and urine:

  • Hantavirus – Rare but often fatal respiratory disease spread via saliva, urine, and droppings.
  • Lymphocytic choriomeningitis – Spread through droppings and causes fever, muscle aches, vomiting.
  • Rat bite fever – Bacteria in saliva causes fever, headache, vomiting.
  • Salmonellosis – Spread by infected mice feces and causes diarrhea.
  • Leptospirosis – Bacteria in urine causes fever, chills, vomiting, diarrhea.

They also trigger allergies and asthma symptoms in sensitive people from their droppings, hair, and nesting materials accumulating in infested areas. Timely removal is vital to prevent associated health issues.

Preventing Cotton Mouse Infestations

Prevention involves denying cotton mice access to structures by sealing exterior holes and gaps. Trim vegetation at least 3 feet from foundation walls. Seal any openings wider than 1/4 inch with appropriate materials. Traps and rodenticides in yards and sheds can further reduce local populations.

Eliminate outdoor food sources like pet food, bird seed, compost piles, and fallen fruits/nuts. Indoors, store human and pet foods in sealed metal or plastic containers to deny access. With vigilant sanitation and exclusion measures, cotton mouse invasions can be prevented.

Cotton Mice in Central Florida – Conclusion

The warm, humid climate and native vegetation of central Florida provides prime conditions for cotton mice populations. They readily capitalize on openings and food sources around suburban homes.

Through early structural exclusion, population control, and sanitation measures, cotton mouse infestations can be prevented. Signs like droppings, gnaw marks, nests, and rub marks indicate where cotton mice have breached homes.

Swift intervention with appropriate trapping or rodenticide baits applied by a professional pest control service is recommended if cotton mice become established indoors. With proactive prevention and population reduction, cotton mice can be managed even in Florida’s hospitable environment.