Different Types of Rodents: 8 Common and Uncommon Rodent Species

Oh, rats! Rodents are one of the most encountered pests nationwide. According to a survey from the National Pest Management Association (NPMA), nearly one-third of Americans have had a rodent problem in their home. These creatures are more than a nuisance, as they pose serious threats to your health and property.

Most types of rodents typically invade homes during the fall and winter in search of food and shelter as the climate cools, although they can still pose problems throughout the rest of the year. Most homeowners surveyed reported rodent sightings in the kitchen, as well as the basement and living room to lesser extents.

Rodents are not just unpleasant, they are also capable of triggering allergies and asthma attacks. They can carry disease-causing parasites, such as ticks, fleas, and lice. More alarmingly, rodents serve as vectors for over 35 diseases, including Salmonellosis, Hantavirus and plague.

In addition to health threats, rodents are known to damage drywall as well as wood, and can also chew through electrical wires, increasing the risk of electrical fires.

And the horror doesn’t end there! Once inside, females can breed quickly. For example, a single female mouse can have as many as 12 young every three weeks, allowing infestations to quickly grow.

Rodents invade approximately 21 million U.S. homes each winter. With many rodent species having the ability to squeeze through openings the size of a quarter and some fitting through holes as small as a dime, there are a lot of rodent details to be aware of. Here are some common and uncommon rodent species that could make their way into your home, as well as the recommended prevention techniques to ensure your home is rodent-free. A rodent problem should not be ignored, as it can escalate to a larger issue overnight!

1. Norway Rats

Norway rats are nocturnal social pests, often building shelters close to one another. Like many other types of rodents, Norway rats are widespread and can be found throughout the United States. They often burrow into piles of garbage or underneath concrete slabs. This species tends to enter homes in the fall when outdoor food sources become scarce, typically nesting in basements, crawlspaces, and other undisturbed dwellings once inside.

These rodents are known to gnaw through almost everything – including plastic and lead pipes – to obtain food and water sources for survival. They eat several times a day and characteristically forage at dusk and again before dawn. Norway rats eat practically anything but show a preference for meat, fish, cereals, and dog food.

Norway rats can cause serious property damage by gnawing through various materials, and they have a unique ability to fit through holes as small as a ½ inch, or the size of a quarter. This not only poses a threat to the structural integrity of homes but also increases the risk of infestations.

In terms of health threats, Norway rats are carriers of various diseases, including plague, jaundice, rat-bite fever, cowpox virus, trichinosis and salmonellosis. They can also contaminate food and introduce fleas and mites into the home.

To prevent Norway rat infestations, it’s crucial to keep a close eye out for signs such as droppings, gnaw marks, damaged food goods, and grease rub marks. An infestation can rapidly grow, so detecting and dealing with potential intruders promptly is essential for the well-being of your home and health.

2. Roof Rats

Roof rats, also known as black rats or ship rats, get their name from their tendency to find shelter in the upper parts of buildings or trees. Thought to be of Southeast Asian origin, roof rats can now be found throughout the U.S. coastal states and the southern third of the country. Although they only live up to one year, roof rats can produce as many as 40 new offspring during their lifetime.

Historically, roof rats and the fleas they carry have been associated with spreading the bubonic plague. Although cases are rare, roof rats also spread diseases such as typhus via fleas, infectious jaundice via urine in water or food, rat-bite fever via bites, trichinosis via undercooked pork and salmonellosis via droppings. Like other rodents, roof rats may show aggression and bite or chase when threatened.

Roof rats typically live in colonies and prefer to nest in the upper areas of structures or trees. They are also excellent swimmers, earning them the nickname “ship rat.” If you have any fruit trees on your property, promptly clean up any fallen fruit, as this can attract roof rats. Additionally, ensure that garbage is stored in tightly closed receptacles to discourage their presence.

3. House Mice

House mice are the most common rodent species encountered, found throughout the Unites States. They prefer dark and secluded areas, often building nests out of paper products, cotton, packing materials, wall insulation and fabrics. These adaptable rodents breed rapidly and can quickly adjust to changing conditions—a female house mouse can produce up to 35 young per year.

In their quest for shelter, house mice are excellent climbers, capable of jumping up to a foot in height, allowing them to reach isolated or withdrawn areas inside structures. Despite having poor vision and being color blind, they make up for it with other enhanced senses.

While this rodent species may seem harmless, house mice can cause significant property damage by chewing through materials like drywall and insulation. Their gnawing on wires inside homes has even been known to spark electrical fires. Beyond the threat to property, house mice pose serious health risks as carriers of diseases such as Salmonella. They contaminate stored food and bring fleas, mites, ticks and lice into your home. 

Micro droplets of mouse urine and inhaling dust that contains dried feces may cause allergies or asthma flare-ups, especially in children. Given their preference for dark and sheltered areas, house mice tend to hide amongst household clutter. To prevent infestations, it’s crucial to keep storage areas clean and well-organized, storing boxes off the floor. Additionally, keeping food in sealed, rodent-proof containers will help you ensure you are not attracting any unwelcome intruders.

4. Deer Mice

Deer Mice get their name from their fur, which closely resembles that of a deer. Found throughout the United States, they prefer to nest in rural areas in places like old fence posts, tree hollows, and log piles. While deer mice are rarely a problem in residential settings, they can wander indoors during the winter months, searching for shelter and food. In the off season, they may take up residence in homes, sheds, barns, cabins, garages and vehicles.

This deceptively cute rodent, with a bicolored tail half brown and half white, poses serious medical concerns. Deer mice are the most common carriers of hantavirus when dust particles contaminated with the urine, feces or saliva of infected deer mice are inhaled.

To prevent potential health risks, it’s important to store pet food or birdseed in secure containers within household areas. Avoid keeping them in places like garages or storage sheds, where they are more accessible and attractive to deer mice.

5. Tree Squirrels

Less commonly thought of as a type of rodent, “tree squirrels” is an all-encompassing term for several squirrel species, including fox squirrels, gray squirrels, flying squirrels and pine squirrels. Tree squirrels, often found in wooded and urban areas with trees, get their name from the fact that they nest, avoid predators and harvest food in trees.

These squirrels can become household pests as they frequently enter homes in the winter, and some species use attics to build their nests. Once indoors, tree squirrels can cause considerable damage to heat and air conditioning systems if they enter electrical equipment rooms. Although they rarely pose a health threat to homeowners, tree squirrels may bite when disturbed.

6. Voles

Voles, also called meadow mice or field mice, are compact rodents with stocky bodies, small eyes and partially hidden ears. These creatures, which are active day and night, eat plants, seeds, bark, crops, insects and animal remains. Voles can cause substantial damage to orchards, tree plantings and field crops, especially when they build extensive runway and tunnel systems. They can also ruin lawns, golf courses and ground covers.

7. Groundhogs

Groundhogs, also known as woodchucks or whistle pigs, commonly invade cropland and vegetable gardens, eating or destroying vegetables and landscape plants. Groundhogs are considered nuisance pests because they can cause extensive damage to home gardens, farms, orchards and field crops due to their feeding and burrowing habits. They sometimes den in crawlspaces around the home.

When burrowing, groundhogs have often destroyed building foundations, created unwanted holes in lawns and caused electrical outages from gnawing on underground wires. People around the country celebrate Groundhog Day every year on February 2. This tradition centers around the idea of a groundhog emerging from its hibernation to "predict" the weather.

8. Prairie Dogs

Prairie dogs are stocky, burrowing rodents that live in colonies and are mainly in the Great Plain region of North America. All prairie dog species prefer open areas of vegetation, commonly inhabiting grasslands. The most widely distributed species is the black-tailed prairie dog, named for its black-tipped tail. This species is most active in the summer months and spends its days foraging.

Prairie dogs rarely come in contact with humans; however, they can carry diseases like the plague and threaten local vegetation and livestock due to their continual feeding habits. Prairie dogs also bring another threat in the form of rattlesnakes and black widow spiders, frequently found in prairie dog towns. Bites from both pests are rare but can be fatal.

Rodent Prevention Tips

• To keep all different types of rodents out, ensure that all holes larger than a dime and gaps wider than a pencil are sealed with a silicone-based caulk, steel wool, or other construction material.
• Install a mesh cover over chimneys and other exposed openings and make sure tree limbs are cut back 6-8 feet from the roofline.
• Store food in sealed glass or metal containers and leave surfaces clear of crumbs and food morsels, which may attract different types of rodents.
• Inspect items such as boxes, grocery bags and other packages brought into the home.
• Keep attics, basements and crawl spaces well-ventilated and dry.
• Store firewood at least 20 feet away from the house and keep lawns, vegetation and cultivated areas well-trimmed by mowing, spraying or grazing.
• If you find rodent feces, hear sounds of scurrying in the walls or observe other signs, contact a licensed pest professional to inspect and treat the pest problem.

Rodent control and management are essential for health and safety reasons. Do not hesitate to act if you suspect an infestation, as a small problem can become a big issue when left untreated. Visit our ‘Find a Pro’ page to get in touch with a licensed pest control professional in your area.

Related Articles and Sources:

• Rodents 101
• How to Get Rid of Squirrels
• 10 Easy Tips to Prevent Mice and Rodents Inside the Home