Did you find a mouse or a rat in Louisiana?
First, I hope it was outside and NOT in your house. 🙂
Second, I’m guessing you’re here to try and identify the correct species. Luckily, you’ve come to the right place! I’ve compiled a list of the most common mice and rats that live in Louisiana, with photos and range maps to help find the one you’re looking at.
Unfortunately, mice and rats can be hard to identify. First, many species look similar to each other. In addition, due to their shy nature and small size, it can be hard to get a good look. You may want to consider purchasing the book below if you need additional help with rodent identification.
Here are 9 COMMON Mice and Rats Found in Louisiana!
#1. Brown Rat
- Rattus norvegicus
The Brown Rat is among the most widespread rats in Louisiana!
It goes by many names, including the common rat, street rat, and sewer rat. You may also know it as the gray rat or Norway rat.
Interestingly, the Brown Rat isn’t native to North America. Instead, it’s thought to have originated in China and Mongolia.
Look for Brown Rats anywhere people are living, particularly in urban environments. They’re best known for living in sewer tunnels and subway systems, scavenging food from the trash.
Although many people find rats off-putting, others keep a sub-species of Brown Rats as pets. This subspecies, called the Fancy Rat, was bred specifically for the pet trade. Besides companion animals, rats can be trained for many jobs to assist humans, like detecting gunpowder for forensic teams and providing therapy support.
It’s a misconception that Brown Rats spread bubonic plague. In actuality, it’s more commonly spread through ground squirrels! Regardless, Unfortunately, they can still transmit infections of many kinds though as their blood can carry several diseases,
#2. Black Rat
- Rattus rattus
The Black Rat is a naturalized species in North America. It’s thought to be native to India but was transported here on cargo ships and has become so widespread that it’s no longer considered a foreign species.
It’s considered a pest in the agricultural market because it feeds on a wide variety of crops. Like other rodents, Black Rats can carry pathogens in their bodies. While they may not appear sick, they can spread infections like toxoplasmosis, typhus, and bubonic plague.
In many areas where the Black Rat was once the dominant species, the Brown Rat has taken over. Black Rats are slightly smaller and reproduce less often, which are two of the reasons this species isn’t as widespread as Brown Rats.
Black Rats go by many common names, such as ship rat, roof rat, and house rat.
#3. House Mouse
- Mus musculus
Most mice in Louisiana can live around people, but few thrive as well as the House Mouse!
If you picture a small, mischievous cartoon mouse when you think of mice, then you’re probably familiar with this species! House Mice have the characteristic large ears, thin tails, and tiny bodies of a typical “mouse.” They do incredibly well in highly populated areas, and there are now more semi-tame populations than wild. These populations live near people and depend on them for food and shelter.
House mice are the most common species to find inside your home because they’re so adaptable to human presence. They readily eat food scraps, build their nests in walls or dark attics and basements, and spend most of their time hidden from view. In fact, you’ve likely shared your home with a House Mouse at least once over the years. Although most people would prefer not to have them, they aren’t the worst roommates!
Like their eating habits, they are adaptable in their social behavior. Populations of House Mice that have an excess of food, like those that live in buildings, form a hierarchy with leaders and followers. However, in the wild, where food is less plentiful, females aggressively protect their territory from one another.
#4. Eastern Woodrat
- Neotoma floridana
Eastern Woodrats live in swamps and forested areas and build their nests in protected spots like the base of trees or boulders. They use various materials to construct their nests, including sticks and branches, rocks, dry dung, tin cans, and even glass shards. This species isn’t picky about building materials!
They’re opportunistic feeders and commonly eat plant matter, including stems, roots, foliage, nuts, seeds, buds, and fruits.
Although they’re laid-back regarding what they eat and where they live, Eastern Woodrats are extremely territorial. Unlike some other rats in Louisiana, this species will nearly always defend its territory jealously. They only become social during the breeding season.
#5. Golden Mouse
- Ochrotomys nuttalli
Unlike other mice in Louisiana, Golden Mice are picky eaters and almost exclusively eat seeds.
The Golden Mouse is named for its soft fur, ranging in color from a golden brown to burnt orange. Look for them in thick woodlands and swamps where they hide in vegetation. They’re especially fond of red cedar and honeysuckle plants.
Their tails are prehensile, which means they’re used as an extra appendage for balance, standing on two legs, and aid in climbing or running.
#6. White-footed Deer Mouse
- Peromyscus leucopus
Like other mice in Louisiana, this species is a vector, which means it carries and spreads disease.
Many rodents can carry disease-causing pathogens without getting sick, making them ideal carriers for these germs. For example, hantavirus, which causes severe disease in humans, and the bacteria that cause Lyme disease are transmitted by this mouse.
Although many people keep White-Footed Deer Mice as pets, there are probably more people that live with this species unwillingly! That’s because this is one of the most likely species to find in your attic, garage, or basement. Even though they can spread disease, contamination isn’t very common in homes.
This is the species I’ve found in my house, and I use a live trap and release them in a field a few miles away. Here’s the one I use!
#7. Cotton Mouse
- Peromyscus gossypinus
You’re likely to find Cotton Mice in a variety of habitats, including forests, swamps, fields, and rocky bluffs. They’re omnivorous and opportunistic but favor seeds and insects as their main food sources.
Cotton Mice earned their common name from using raw cotton in their nests. Although they rarely live longer than a year, this species has a unique talent for surviving wildfires and predators! It often spends time underground, where it can stay protected from these threats.
While wildfires will severely impact nearly every other species in Louisiana, the Cotton Mouse’s population can remain largely unaffected.
#8. Fulvous Harvest Mouse
- Reithrodontomys fulvescens
Mating pairs of Fulvous Harvest Mice will often share a nest even if they aren’t actively raising young, which is unusual for mice in Louisiana. Look for them in grassy areas with open pine or mesquite woods. They build their nests, made of tangled grasses, a few inches off the ground.
Outside the nest, Fulvous Harvest Mice spend most of their time in low shrubs. They eat insects and invertebrates and supplement this diet with seeds during colder temperatures.
#9. Eastern Harvest Mouse
- Reithrodontomys humulis
Eastern Harvest Mice are widespread in Louisiana and plentiful in grassy fields and meadows. They have dark brown fur, lighter fur on the belly, and light tan or white feet. They avoid forested areas and instead build nests that they live in throughout their life.
Eastern Harvest Mice have short lifespans.
Females in the wild rarely live longer than a year, and the oldest recorded individual in a laboratory lived to 2 years and 2 months.
Do you want to learn about other MAMMALS in Louisiana? Check out this field guide!
- 20 COMMON Mammals in Louisiana! (ID Guide)
Which of these mice and rats have you seen before in Louisiana?
Tell us below in the COMMENTS section!