Guide to Rodents in Washington DC

Rat tails

According to a nationwide survey, nearly 40% of homeowners have seen a rodent in their home, and where there’s one, there are almost always more. Does one mouse mean an infestation? Not always, but keep in mind that a mating pair of mice can produce as many as 12 babies every three weeks.

Since these critters can wreak all sorts of havoc—from spreading disease to damaging property—it’s essential to familiarize yourself with the kinds of rodents that infest homes. Read our guide to learn about the species that take up residence in homes and how to quickly identify them.

What Is a Rodent? 

Rodents are an order of mammals characterized by their larger-than-average front teeth, which they use to gnaw, find shelter and obtain food. These animals live on every continent except Antarctica and even most islands. 

While the word “rodent” may bring to mind the words “mouse” and “rat,” this enormous order of animals encompasses over two dozen families and includes groups as diverse as beavers, porcupines, marmots, and chinchillas. 

There are three main groups of rodents.

  • Mouse-like rodents:  Mouse-like rodents have long whiskers and pointed faces.
  • Cavy-like rodents: Cavy-like rodents have large heads, sturdy bodies, and short tails. The guinea pig is a well-known example. 
  • Squirrels: Squirrels, with their bushy tails and long, flexible bodies, are a familiar sight in many parts of the world. 

Rodents are generally small and tend to be prey for larger animals. For this reason, they have developed sharp senses that help them spot danger and faster reflexes that enable them to escape quickly from a dangerous situation. 

There are 2,227 species of rodents, which comprise over 40% of all mammal species. Several factors have contributed to the evolutionary success of rodents, including their short breeding cycle, small size, and ability to eat a vast array of different foods. Regardless of their body form, rodents all possess the same fundamental tools that they use to cut, slice, pry, dig, gouge, stab or hold, which allows them to feed on a wide variety of foods. 

Fossil evidence suggests rodents have inhabited this planet for 56 million years or longer, while modern humans have been around for less than a million. However, despite this short overlap, the impact that humans have had on rodent evolution is profound. 

Whereas early humans were just another predator for rodents to avoid, when homo sapiens transitioned from being nomadic to practicing sedentary agriculture, they became reliable sources of shelter and food for various rodent species. 

Rodents have impacted human populations in a variety of ways, ranging from mildly inconvenient to deadly. They’ve destroyed crops, contaminated food with their feces, caused leaks from burrowing, and damaged objects by gnawing. Specific rodent species have carried diseases like plague, scrub typhus, murine typhus, rat-bite fever, tularemia, hantavirus, Lassa fever, Rocky Mountain spotted fever, and countless other deadly diseases. 

Rodents can be nocturnal, diurnal, or active during part of the night and day. The diets of most rodents include both animal and vegetable matter, although some herbivorous species exist as well.  

How to Tell If You Have a Rodent Infestation

There are several clues you can use to spot rodents in your home. Keep your eye out for the following.

  • Droppings: Droppings are a definite sign that mice or rats are present. You can use them to determine the type of rodent, how large the infestation is, and where they’re most active. For instance, mouse droppings are small and pointed at both ends, whereas Norway rat droppings are larger and blunt at both ends.  
  • Urine smell: Rodent urine has a pungent, musky smell. It’s easy to smell if you have an infestation. 
  • Gnawed holes: Holes gnawed by mice tend to be clear-cut, small, and measure roughly the size of a dime. Holes gnawed by rats, on the other hand, are larger, measuring the width of a quarter. 
  • Gnaw and rub marks: Rodents leave oily rub marks along the walls where they travel. If you can smear the rub marks, that means they’re fresh. Rodents also leave behind gnaw marks on the wood. 
  • Nests: You can also figure out the type of rodent by the nest it builds. For example, mice build indoor nests with string, shredded paper, and various other pliable materials. Norway rats, in contrast, tend to build nests outside and deep in the ground. 
  • Noises: Rodents are generally nocturnal, and at night, you can often hear them scratching when they run along floors and inside walls. 
  • The behavior of your pets: Pets may act strangely if they smell or hear rodents in your house. They might appear very alert or start pawing at spaces under stoves, refrigerators, or other pieces of furniture with low clearance. 


Mice are some of the smallest rodents, although also among the most successful. They tend to have hairless, long tails and pointed snouts. They live in a wide variety of environments, including, fields, woods, mountains, and deserts. Species like the house mouse have evolved to live together with humans, making nests in their homes and eating their food scraps. 

In this section, we’ll cover what attracts mice to your house, as well as the types of mice you're mostly like to encounter in your home: the house mouse and the deer mouse. 


House Mice 

The most common mouse type in the United States, the house mouse is only one or two inches long, excluding its tail. Although typically a grayish, brown color, many color variations exist. 

The house mouse is easy to recognize by its hairless tail, which is as long as its head and body combined. It also has a blunt snout, small eyes, and big ears. 

Their rod-shaped droppings measure about a half-inch in length. They prefer to feed on cereal grains, seeds, or sweets but will eat almost anything edible. They do not require much water, as they get enough from the food they eat. 

They prefer to stay inside, and some house mice in urban areas spend their whole lives inside buildings. However, in rural or suburban areas, they live outside in weeds, storage sheds, and garages, but will often move inside during the colder months when food is scarcer. 

You may wonder how to find mouse holes. They don’t look much like the stereotypical holes depicted in cartoons. Mouse holes, both inside and outside buildings, can be small cracks, gaps, or spaces that serve as access points to their nests.

When inside, house mice build their nests near food sources, such as under ovens or refrigerators. Every day, they make 20 to 30 visits to their food sources within their territory, which ranges from 10 to 30 feet from their nest. 

They’re skilled climbers and can scale any rough vertical surface. They can also run along ropes and wire cables and jump an impressive 13 inches upward. 

You can use rodent bait or mice traps to control and rid your home of house mice. To prevent them from entering, do the following.

  • Seal openings: Plug up any access points larger than a quarter of an inch. Also, seal cracks and openings around the foundation, as well as openings around vents, utilities, and pipes. 
  • Check the seals on your doors and windows: Your windows, doors, and screens should fit snugly into their frames. 
  • Mouse-proof your food: Keep all used, processed, and stored food away from house mice. Store grains and meat in metal canisters, glass jars, or resealable airtight containers. 

Deer Mice

Deer mice tend to live in more rural places, and they rarely enter homes or buildings. However, they may seek shelter indoors during the winter. 

They tend to live in burrows they’ve made or the abandoned burrows of other animals, in stumps, beneath rocks, in debris, soil cracks, or any other protected place. 

Deer mice measure around six inches in length, including their tail. Their upper body is usually darker and their undersides are white. 

To rid deer mice from your home or prevent them from entering, follow the same steps as with house mice. 


Rats are long-tailed, medium-sized rodents that belong to the superfamily Muroidea. The genus Rattus, known as “true rats,” includes different types of rats important to humans, such as roof rats and Norway rats. Below, we will discuss each species.

Roof Rats 

Roof rats, also known as black rats and house rats, thrive more in warmer climates. Norway rats have largely driven them out of colder climates. However, some studies have shown that roof rats have been able to adapt to harsher, more extreme climates. 

A full-grown roof rat measures roughly five to seven inches long, not including its tail, which measures roughly another six to nine inches in length. Their color ranges from light brown to black and tends to feature a lighter underside. 

What attracts rats to your house? Roof rats are omnivores and eat many different types of foods, including fruits, seeds, stems, fungi, leaves and various invertebrate and vertebrate species as well. As they are generalists, they do not have very specific food preferences, as evidenced by their tendency to eat any meal given to pigs, cows, chickens, dogs, and cats. They threaten several natural habitats because they also eat insects and birds and are a big nuisance to farmers, as they tend to eat a wide variety of crops, including cereals, coconuts, sugarcane, cocoa, coffee beans, and oranges. 

Roof rats usually forage after dusk, and if they cannot eat the food quickly, they’ll find a place to store it for later. 

Norway Rats

Norway rats, also known as brown rats, have coarse fur that is typically dark gray or brown, and their underparts are usually brown or light gray. They are quite large, weighing sometimes twice as much as black rats and several times more than house mice. Their length ranges from eight to 10 inches excluding the tail, which measures another seven to 10 inches, roughly the same length as their bodies. Males tend to weigh around 12 ounces, whereas females weigh around nine ounces. Reportedly, some individuals can weigh as much as 25 ounces. You may have heard stories about Norway rats being as big as cats, but these are either exaggerations or confusions with other species, such as the muskrat or coypu. 

Often seen in waterways and urban areas, these rats are good swimmers, sometimes even being referred to as “water rats.” They are also mostly nocturnal, becoming active around sunset when they start looking for water and food. Certain individuals may also be active during the daytime in places with high rat populations. 

Norway rats, like other rodents, can carry various disease-causing pathogens, including rat-bite fever, viral hemorrhagic fever, hantavirus, and cryptosporidiosis. 

Rats have exceptionally poor eyesight and are colorblind. They instead rely on their hearing, as well as their acute senses of taste, smell, and touch, to get around and find food. Therefore, for reasons of safety, it’s possible to dye bait unusual colors without deterring rats, as long as it doesn’t have a repellent odor or taste. Their excellent sense of taste allows them to detect contaminants in their food at extremely low levels. 

Norway rats tend to build their nests either at ground level or in underground burrows. They line their nests with cloth, shredded paper, and other fibrous materials.

Are Rodents Dangerous?

While rodents are not likely to bite you unless you provoke them, they do pose a danger in terms of the harmful diseases they can carry. When scurrying through your cabinets, over your countertops, and under your sink, they’re spreading whatever diseases they happen to be carrying. Their germs and bacteria end up on your dishes, food, dining areas, and bathroom surfaces, meaning they’re basically delivering sickness straight to everyone in your household. 

Contact Senate Termite & Pest Control 

If you’re a Maryland or Northern Virginia homeowner concerned about rodents in or around your house, Senate Termite & Pest Control is the solution you’re looking for. We use bait placement and nontoxic control measures to best suit your needs and evict your unwanted visitors as quickly and efficiently as possible. Since our beginnings in 1991, we have provided our pest control services to over 20,000 customers in the area. 

When hiring Senate Termite & Pest Control, we guarantee you will experience all the following.

  • Prompt, friendly service: We work around your busy schedule.
  • Affordable solutions: We offer options to suit your needs and budget. 
  • Eco-friendly treatment options: We offer these at no additional cost. 
  • Reliable technicians: Our technicians all have extensive experience and training. 
  • High-quality service: We provide premium service for your complete satisfaction.  
  • Personalized care: We strive to offer the same friendly, personal touch you would expect from your neighbor. 

You can contact us via our online form or by calling us at 800-433-9409. 

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