What are Rats? Understanding These Adaptable Rodents

Andrew Peluso
August 27, 2024

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Rats are fascinating and complex creatures that have coexisted with humans throughout history. These medium sized, long tailed rodents belong to the order Rodentia, with the most well-known species found in the genus Rattus. While there are 56 recognized rat species worldwide, the brown rat (Rattus norvegicus) and the black rat (Rattus rattus) are the most common and widely distributed. Rats are highly adaptable animals that thrive in diverse environments from urban areas to remote islands. Their intelligence, social nature, and ability to form close bonds with humans have led some people to keep them as pets. However, their notoriety as unwanted intruders often overshadow their positive qualities. Understanding these complex creatures is crucial for managing their interactions with humans and preserving ecological balance.

Table of Contents

What Do Rats Looks Like?

These medium sized rodents are typically distinguished by their long, slender bodies and prominent tails, which can vary in length from slightly shorter than the body to noticeably longer. Their tails typically appear smooth and hairless but are actually covered with fine, short hairs. Rats generally have pointed heads, large eyes, and visible ears, though the size and shape of these features can differ between species. Their bodies are supported by moderately long legs ending in sharp claws, with hind feet featuring fleshy pads on their bald soles. The coloration of rats is quite varied and ranges from common shades like black, brown, gray, and white to less frequent hues such as red. Some rats, particularly those bred as pets, may display spotted or multi-colored coats. While rats share similarities with mice, they are generally larger and have distinct characteristics such as squarer heads and proportionally smaller ears.

How Big Do Rats Get?

The size of rats can vary significantly across different species. Generally, rats are characterized by body lengths that exceed 5 inches (12.7 cm), with weights rarely surpassing 18 ounces (510 grams). Among the various rat species, there’s a considerable spectrum of sizes. For instance, most average household rats weigh between 5 to 18 ounces ^[1] with a body length of 6.7 to 8.3 inches (17 to 21 cm) with tails that are usually equivalent to the length of their body. At the smaller end of the scale, we find species measuring just 4.7 to 6.7 inches (12 to 17 cm) in body length, while larger species can reach lengths of 7.5 to 10.6 inches (19 to 27 cm). The largest rat recorded is the recently discovered Bosavi woolly rat, which astoundingly measures up to 32.2 inches (82 cm) from nose to tail and weighs around 3.3 pounds (1.5 kg) which is roughly the size of an average domestic cat.

Rat Species

The rat family encompasses a diverse array of species, with over 56 distinct types identified worldwide. Among this varied group, two species stand out as the most prevalent in the United States: the Norway rat (Rattus norvegicus) and the Roof rat (Rattus rattus). These “true” rats, belonging to the genus Rattus, are the ones most commonly associated with urban environments and human habitations. However, the term “rat” is often applied more broadly to include several other rodent species that, despite their common names, are not technically classified within the Rattus genus. Examples of these include the pack rats (genus Neotoma), kangaroo rats (genus Dipodomys), and bandicoot rats (genus Bandicota). While these animals share some similarities with true rats and belong to the broader Murine rodent family, they possess unique characteristics that set them apart from their Rattus cousins.

What Do Rats Eat?

Rats exhibit a broad diet that varies depending on the rat’s species and habitat. While it’s often believed that rats will eat anything, this is an oversimplification of their dietary habits. Many rat species are opportunistic omnivores that have evolved to thrive on a wide range of food sources from stored grains and discarded human food to small insects. The dietary needs of rats are substantial, with many species requiring daily food intake equivalent to about one third of their body weight. This high metabolic demand, coupled with their adaptability, has led to rats developing impressive foraging skills and even food storing behaviors reminiscent of squirrels. A rat’s diet can also include unconventional items like soap, leather, and animal waste which showcases their remarkable ability to consume just about anything to survive.

What Attracts Rats?

Rats are drawn to environments that provide them with the essential elements for survival: shelter, food, and water. Understanding what attracts these resourceful creatures is crucial for effective pest management. Here’s a list of common rat attractants:

Food sources:
- Unsealed garbage and compost bins
- Pet food left outdoors
- Bird feeders and fallen seeds
- Fruit and nut-bearing trees (e.g., lemons, oranges, avocados, walnuts)
- Vegetable gardens
- Improperly stored food in pantries or garages
Water sources:
- Leaky pipes and faucets
- Standing water in birdbaths or pet bowls
- Poor drainage areas
- Clogged gutters
Shelter opportunities:
- Cluttered storage areas
- Overgrown vegetation and dense bushes
- Woodpiles and leaf litter
- Gaps in building foundations or roofs
- Unused or rarely disturbed spaces (attics, crawl spaces)
Warmth and comfort:
- Heat emissions from buildings
- Cozy nesting materials (e.g., paper, fabric, insulation)

By getting rid of these attractants, homeowners can significantly reduce the likelihood of rat infestations and create an environment less appealing to these persistent pests.

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Where are Rats Found?

Rats have demonstrated an exceptional ability to adapt across diverse environments which is what makes them one of the most widely distributed mammals on the planet. Their global presence that spans every continent except Antarctica ^[2] is closely tied to human activity, as rats have skillfully exploited the food sources and shelter opportunities provided by human settlements. From bustling urban centers to remote rural areas, rats have successfully integrated themselves into nearly every type of human inhabited ecosystem. Their absence in Antarctica is due to the extremely cold temperatures that make outdoor survival impossible for these creatures, coupled with the lack of necessary resources.

Rat Habitat

While some rat species inhabit natural settings like forests, fields, and tropical islands, the most common species have become closely associated with urban areas that are populated by humans. These opportunistic survivors have mastered the art of exploiting human environments for their benefit. When selecting a nesting site, rats prioritize three key factors: warmth, proximity to food and water sources, and access to suitable nesting materials. However, the specific preferences for nesting locations can vary between species. For instance, Norway rats typically favor ground level or below ground habitats where they often construct burrows beneath structures or in basements. Roof rats, on the other hand, tend to seek elevated nesting sites in trees or building attics. Regardless of the species, rats demonstrate incredible resourcefulness in utilizing available materials to create comfortable, protected nests. Their ability to inhabit diverse settings, from urban sewers and landfills to rural fields and human dwellings, shows their extreme adaptability and explains their widespread success as a species.

How Do Rats Get Inside?

Rats use their intelligence, agility, and physical capabilities to overcome various obstacles. These resourceful rodents also possess an uncanny ability to identify and exploit potential entry points, whether pre-existing or self-created. Their problem solving skills enable them to navigate complex environments and overcome barriers designed to keep them out. Rats can squeeze through incredibly small openings, with some species capable of compressing their bodies to fit through gaps as narrow as a quarter of an inch. When faced with solid barriers, they don’t hesitate to use their powerful incisors to gnaw through materials like wood, plastic, and even soft metals. Their strong legs, sharp claws, and long tails give rats climbing abilities that allow them to scale vertical surfaces and access elevated entry points such as rooftops or upper story windows. Some rats have even been known to enter buildings through unconventional routes like swimming through plumbing systems and emerging via toilets.

Signs of Rat Infestation

Recognizing the signs of a rat infestation is crucial for early detection and effective management. Here are key indicators that suggest rat activity in your home or property:

Rat Droppings: Small, dark, pellet-shaped feces that are often found along walls or in hidden areas.
Gnaw marks: Visible teeth marks on wood, plastic, or even metal surfaces indicate rats attempting to access food or nesting materials.
Grease marks: Dark, oily smears along walls and baseboards from rats’ fur as they repeatedly travel the same paths.
Unusual noises: Scratching, scurrying, or squeaking sounds, especially at night when rats are most active.
Nests: Accumulations of shredded paper, fabric, or other soft materials in secluded areas like attics or wall voids.
Tracks: Footprints or tail drag marks in dusty areas or mud.
Burrows: Small holes near foundations, fences, or dense vegetation.
Disturbed food packaging: Chewed boxes or bags, particularly in pantries or storage areas.
Urine stains: Urine is visible under ultraviolet light and has a strong, musky odor.
Rat runways: Worn paths along walls, fences, or rafters where rats frequently travel.
Sightings: Seeing rats, especially during daytime, can indicate a significant infestation.
Pet behavior: Unusual excitement or distress in pets, particularly at night, may signal rat presence.

Identifying these signs early can help in implementing timely rat control measures and preventing a full blown infestation.

Rat Reproduction

Rat reproduction is a remarkably efficient process that contributes significantly to their success as a species and their potential to become problematic in human environments. The reproductive capabilities of rats vary somewhat between species, but generally most species are capable or reproducing at a rapid rate. Taking the brown rat as a prime example, these rodents reach sexual maturity around three months. The gestation period is relatively short, lasting on average between 21 to 23 days ^[3], after which a litter of pups is born. Litter sizes can range dramatically, from as few as two to as many as 16 pups, with an average of 8 to 12 offspring per litter. In optimal conditions, a female rat can typically produce a litter every other month which can potentially yield over 60 pups annually. This rapid reproductive rate is further enhanced by the fact that females can become pregnant again within 48 hours of giving birth.

Rat Lifespan

The lifespan of rats is a subject that varies significantly between wild and captive populations, as well as among different rat species. In their natural habitats, rats face numerous challenges that can dramatically shorten their lives including predation, disease, competition for resources, and human intervention. Consequently, the average lifespan of a wild rat is surprisingly brief and typically only ranges from six months to a year ^[5]. However, the story changes considerably for rats living in captivity or as pets. Without the constant threats present in the wild, domesticated rats can live significantly longer and often reach two to three years of age. It’s worth noting that despite their relatively short individual lifespans, rat populations can persist and thrive due to their rapid reproductive cycles that allow for quick generational turnover.

Are Rats Dangerous?

Rats pose various risks to human health and property, making them a significant concern for both urban and rural communities.

Rat Disease

Rats pose a significant health risk to humans due to their capacity to transmit a wide array of diseases. These rodents serve as vectors for numerous pathogens that can spread serious illnesses through various means. Direct transmission can occur through rat bites or contact with their bodily fluids, while indirect transmission often involves exposure to rat urine, feces, or parasites that infest rats. Some of the most notorious diseases associated with rats include bubonic plague, leptospirosis, salmonellosis, and hantavirus pulmonary syndrome. In urban environments, rats can contaminate food and water sources which can result in outbreaks of foodborne illnesses. Additionally, rats can harbor ectoparasites like fleas and mites, which can cause secondary infections or allergic reactions in humans. Rats’ close proximity to human settlements and their disease carrying potential make them a persistent threat to public health, particularly in densely populated areas or regions with poor sanitation.

Rat Bites

Rat bites, while relatively uncommon, can pose serious health risks when they do occur. These incidents typically happen when rats feel threatened or cornered which prompts them to react defensively. Although rats generally prefer to avoid direct confrontation with humans, certain situations, such as inadvertently disturbing a nest or attempting to handle a wild rat, can lead to bites. The primary concern with rat bites beyond the immediate physical injury is the potential transmission of diseases. Rat bite fever, caused by bacteria present in rat saliva, is one of the most significant risks associated with these incidents. The risk of infection is further compounded by the fact that rats’ teeth are sharp and can create deep puncture wounds, which are prone to bacterial contamination. Given these risks, any rat bite should be treated as a medical emergency and should be immediately cleaned and inspected or treated by a medical professional.

Rat Damages

Rat infestations can lead to extensive and costly damage to both residential and commercial properties. These rodents’ constant need to gnaw, driven by their ever-growing incisors, results in significant structural damage to buildings. They chew through various construction materials, including wood, drywall, and even concrete. Another particularly dangerous aspect of rat damage is their tendency to gnaw on electrical wiring, which not only disrupts electrical systems but also significantly increases the risk of fire outbreaks. Beyond structural concerns, rats wreak havoc on personal property. They shred fabrics, papers, and other soft materials to create nesting sites. This results in the destruction of valuable items like clothing, books, and important documents. In vehicles, rats can cause severe damage by chewing through wires, hoses, and belts which can render the vehicle inoperable. Agricultural settings also face substantial economic losses due to rats consuming and contaminating crops both in fields and in storage. The cumulative effect of these damages translates into millions of dollars in repair and replacement costs annually.

Are Rats Invasive?

Rats, particularly the black rat (Rattus rattus) and the brown rat (Rattus norvegicus), are considered among the world’s most problematic invasive species. Their invasive nature stems from their remarkable adaptability, high reproductive rates, and their long history of unintentional human assisted dispersal. As stowaways on ships, these rodents have been inadvertently introduced to ecosystems worldwide. The impact of invasive rats is particularly severe on isolated ecosystems like islands where native species have evolved without mammalian predators and lack appropriate defense mechanisms. In these environments, rats prey voraciously on native flora and fauna, including birds’ eggs, small mammals, reptiles, and invertebrates which leads to significant biodiversity loss. Their omnivorous diet and ability to outcompete native species for resources further exacerbate their impact. Researchers suggest that rat invasions have played a significant role in the disappearance and possible extinction of numerous seabird and reptile species in these ecosystems.

10 Other Fascinating Rat Facts

Here’s a compilation of intriguing rat facts that showcase their unique characteristics and abilities:

Dental Growth: Rats’ front incisors grow continuously throughout their lives which require constant gnawing to keep them at a manageable length.
Swimming and Climbing: Norway rats are excellent swimmers, while roof rats are remarkably agile climbers capable of scaling vertical surfaces.
Sensory Abilities: Rats can’t see well but their sense of smell and hearing make up for it. Their whiskers are also extremely sensitive and help them to navigate the world around them.
Social Structure: Rats live in colonies with complex social hierarchies, often led by a dominant male.
Flexibility: Their flexible skeletal structure allows rats to squeeze through openings as small as their skull.
Cognitive Abilities: Studies suggest that rats can dream and even visualize desired future outcomes. They are known to be able to problem solve, navigate mazes, and perform actions for rewards.
Resilience: Some rat species can survive falls from significant heights, with black rats reportedly withstanding falls of up to 50 feet.
Human Interaction: While often considered pests, rats have proven valuable in scientific research and have been trained for tasks such as detecting land mines and assisting in search and rescue operations.
Allergies: Rats shed a considerable amount of hair annually, making them problematic for allergy sufferers.
Adaptability: Their ability to chew through various materials including wood, plastic, and even some metals, contributes to their success in diverse environments.

How to Prevent Rats

Effective rat prevention involves a multi-faceted approach that addresses the key factors attracting and enabling rat infestations. Here’s a comprehensive strategy to keep rats at bay:

Sanitation:
- Regularly clean and declutter both indoor and outdoor spaces
- Store food in airtight containers and promptly clean up spills
- Secure garbage in rodent-proof bins with tight-fitting lids
- Maintain a clean compost bin
Exclusion:
- Seal all potential entry points, including small gaps and cracks in foundations, walls, and roofs
- Install metal screens over vents and openings
- Use door sweeps and weatherstripping to close gaps around doors and windows
- Trim tree branches and shrubs away from buildings to limit roof access
Landscaping:
- Remove dense vegetation and overgrown areas near structures
- Keep lawns mowed and free of debris
- Store firewood and building materials at least 18 inches off the ground and away from buildings
Water Management:
- Fix leaky pipes and faucets promptly
- Ensure proper drainage around the property
- Remove standing water sources including pet bowls and birdbaths
Food Source Reduction:
- Clean up fallen fruit and nuts in yards
- Avoid leaving pet food outdoors, especially overnight
- Use rodent-proof bird feeders and clean up spilled seeds
Natural Rat Deterrents:
- Plant rat repelling herbs like mint or lavender around the property
- Use essential oils or commercial repellents in problem areas
Regular Inspections:
- Conduct routine checks of your property for signs of rat activity
- Pay special attention to dark, secluded areas like attics, basements, and crawl spaces
Community Cooperation:
- Work with neighbors to implement rat prevention measures
- Report rat sightings to local health departments or pest control authorities

By implementing these preventive measures, you can significantly reduce the likelihood of rat infestations and create an environment that is less hospitable to these persistent pests.

How to Get Rid of Rats

Exterminating rats requires a strategic and multi-faceted approach that combines different treatment strategies to leverage the benefits of each for a combined effective approach:

Identification and Assessment: Confirm the presence of rats through signs like droppings, gnaw marks, and sightings. Then determine the extent of the infestation and identify entry points to help develop a robust treatment strategy.
Trapping: Use snap traps for quick and effective results but be sure to use attractive baits and place the traps strategically in places that have shown previous recent rat activity. Consider live traps for humane removal but avoid glue traps because of their inhumane nature.
Baiting: Use rodenticides cautiously and only in outdoor areas and be sure to follow all safety instructions and local regulations. Be aware that baits may cause rats to die in inaccessible areas which can introduce other problems.
Professional Help: Consider hiring a pest control professional for severe infestations because they can provide targeted treatments and ongoing management.
Monitoring and Maintenance: Regularly inspect for new signs of rat activity and maintain cleanliness and exclusion measures to prevent rat recurrence.

How to Clean Up After Rats

Cleaning up after a rat infestation is a critical process that requires careful attention to safety and thorough sanitization. The primary concern during rodent cleanup is the potential exposure to dangerous pathogens, particularly hantavirus, which can be present in rat urine and droppings. When these waste materials dry and become airborne, they pose a significant health risk if inhaled or ingested accidentally. To mitigate these dangers, it’s essential to approach the cleanup process with caution and proper protective measures.

Before beginning, ventilate the affected area for at least 30 minutes to help disperse potentially contaminated dust particles.
Personal protective equipment is crucial. This includes wearing a high-quality respiratory mask (preferably an N95 or better), protective eyewear, disposable gloves, and clothing that covers all exposed skin.
When cleaning, avoid actions that stir up dust like sweeping or vacuuming dry droppings. Instead, thoroughly wet contaminated areas with a disinfectant solution and use damp cloths or mops to clean surfaces.
Dispose of all contaminated materials including cleaning supplies in sealed plastic bags.
After cleaning, disinfect all surfaces that may have come into contact with rat waste while paying special attention to areas where food is prepared or stored.

Remember, the risks associated with rat borne diseases make it advisable to consider professional cleaning services for extensive infestations or if you have any health concerns that might make you more susceptible to infection.

Contact Absolute Pest Management if You Are Dealing with Rats

If you’re facing a rat infestation or suspect rat activity on your property, don’t hesitate to seek professional help. Absolute Pest Management has the expertise, experience, and specialized equipment necessary to effectively address rat problems while ensuring your safety. Our team of trained rodent control professionals can provide a comprehensive assessment of your situation, implement targeted control measures, and offer long-term prevention strategies tailored to your specific needs. Contact Absolute Pest Management today for a consultation and take the first step towards a rat free environment. Let our rat exterminators help you reclaim your space and peace of mind with our professional rat control services. We have offices in Austin and Buda, Texas and serve all of our surrounding communities.

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Rat FAQs

What is the purpose of rats?
- Rats play important ecological roles in many ecosystems as seed dispersers, prey for various predators, and soil aerators through their burrowing activities. In urban environments, they serve as indicators of sanitation issues and can help identify areas needing improved waste management. Additionally, rats have contributed significantly to scientific research by aiding in the development of numerous medical treatments and providing insights into mammalian behavior and biology.

What makes a rat a rat?
- A rat is defined by its membership in the genus Rattus, which includes medium sized rodents with long tails, pointed snouts, and sharp incisors that continuously grow. Key characteristics that distinguish rats from other rodents include their larger size compared to mice, their adaptability to various environments, and their complex social behaviors within colonies. Rats are also known for their intelligence, problem solving abilities, and their capacity to thrive in close proximity to human settlements.

Are rats pests or rodents?
- Rats are both pests and rodents, as these terms are not mutually exclusive. As members of the order Rodentia, rats are scientifically classified as rodents which is a group characterized by continuously growing incisor teeth. However, rats are also considered pests due to their tendency to invade human spaces, cause property damage, and pose health risks through disease transmission which makes them a significant concern in urban and agricultural settings.

What are rats caused by?
- Rats are not “caused” by any specific factor, but rather their presence is often a result of environmental conditions that favor their survival and reproduction. Their proliferation in human populated areas is typically facilitated by easy access to food sources (such as unsecured garbage or pet food), available shelter (like cluttered spaces or access points that allow them in structures), and no control measures (like predators or pest control). In essence, rats thrive where human activity provides them with abundant resources and opportunities to establish populations.