Rat Facts & Information
Protect your home or business from rats by learning techniques for identification and control.
Types of Rats
What do rats look like?
Rodents are warm-blooded mammals that, like humans, can be found throughout the world. They have oversized front teeth for gnawing and cheek teeth, which are adapted for chewing. Rodents chew on a variety of items available to them and cause great damage in and around homes.
How do I get rid of rats?
What Orkin Does
Rodents are some of the most adaptable creatures on the planet and can be extremely difficult to exterminate. Rodent infestations can cause considerable damage to infested buildings and local agriculture. They are also known carriers of many diseases and prove a health hazard to humans. Rodent populations grow quickly and steadily, so rodent control is best started prior to infestations. In order to protect your home, garden, and health from existing rodent infestations, professional, customized pest control from an Orkin Pro is often necessary. For help preventing and getting rid of mice infestations, call your local Orkin branch.
Your customized rodent control program may contain:
Exclusion and sealing of sites greater than ½ inch (about the size of a dime) using screens, flashing, door sweeps, and other materials to keep rats from entering a structure.
Interior and exterior sanitation to minimize available food and water that supports a rat population.
Keeping vegetation thinned out or removed from the perimeter of buildings.
Removing clutter and any debris that creates hiding places rats can use as harborage sites.
Using traps and other mechanical means to remove rats.
Rat control using chemical products involves bait designed to kill rats. Care must be exercised to ensure that the bait is properly placed and the use instructions on the product’s label are strictly followed. One of the more common techniques for bait use is to place it n in a tamper-proof rodent bait station that protects the bait from accidental exposure to non-target animals or people. In situations where rats are not controlled with conventional products, fumigation of transport vehicles or rat ground burrows may sometimes be needed.
Behavior, Diet & Habits
How do I identify a rat?
There are numerous species of rats found within the United States, but this article will focus upon those rats that most frequently create pest issues in homes and businesses. These rats are the Norway rat (Rattus norvegicus) and the Roof rat (Rattus rattus). In addition, two other rats, the Rice Rat Oryzomys palustris) and the Cotton Rat (Sigmodon hispidus) will not be elaborated on in this article, but are mentioned since they are identified by the Centers for Disease Control and Prevention as hosts of hantavirus and therefore noteworthy from a public health perspective.
What do Norway rats vs. roof rats look like?
Norway Rats are frequently called brown or sewer rats. They are large, bulked-up looking rats that can grow to lengths of about 13-16 inches when measured from their nose to the tip of their tail. Coloration is primarily gray on their underside and reddish or grayish-brown to black on the top of their body. The ears and tail of the Norway rat are hairless and the tail is shorter than the length of the rat’s body. With blunt snouts, Norway rat adults weigh about 7-18 ounces.
Roof Rats are commonly called black rats and are smaller than Norway rats. Adults range in weight from about 5-10 ounces. Their tails are longer than the rest of their body and are uniformly dark colored. The underside of the roof rat’s body is grayish to white. The muzzle of the roof rat is pointed and the overall appearance of the roof rat is much more streamlined and sleek looking than a Norway rat.
Where do roof rats live?
As mentioned above, roof rats prefer aboveground nesting locations in shrubs, trees, and dense vegetation. Roof rats entering homes are generally found in raised or secure enclosures such as walls, cabinets, attics, and false ceilings. Roof rats are likely to be found in coastal, near-coastal areas and port cities.
Roof rats are adept climbers and not surprisingly are apt to build their nests in locations above ground. However, they may sometimes also build nests in burrows. These rats are primarily active at night. Scientists have noted that the roof rat’s long tail is adapted to enhance its ability to climb and to assist them in balancing. Both roof rats and Norway rats have a well-developed sense of smell and are wary of new things that are introduced into their home range. Roof rats are not accomplished swimmers and are not usually found in sewers.
Where do Norway rats live?
The preferred habitat of Norway rats is just about anywhere people reside. Some of their habitats include garbage dumps, sewers, and fields. In most of our urban areas, Norway rats may be seen scurrying around after dark looking for food in garbage cans and other places where human refuse is found. Their burrowing habitats include soil along building foundations, under woodpiles, and other piles of debris. Should Norway rats infest a structure, they most likely will live in the basement or ground floor. Read more about where rats live.
Norway rats are usually active at dusk or during the night and are inactive during daylight hours. However, when a Norway rat population grows so large that competition from other rats for food, water, and harborage increases, some members of the rat community may seek to find new areas to colonize during the daytime. Norway rats build their nests in underground burrows where they mate, rear their young, store food, and seek refuge from predators. Norway rats can climb, but not as well as roof rats, and are strong swimmers.
What do rats eat?
Roof rats are omnivores and will feed on many types of vegetation such as fruits, grains, seeds and grocery produce. Also, roof rats are likely to consume insects. Just like Norway rats, roof rats destroy far more foodstuffs by contamination from feces and urine than from consumption.
Norway rats are also omnivores and will eat just about anything that is found near where humans discard food. Also, Norway rats may prey upon fish, poultry, mice, birds, small reptiles and amphibians. They may eat vegetation, but prefer to meat or meat-related wastes. Read more about what rats eat.
Rat Reproduction Facts
Roof rats are polygamous and group themselves into colonies of multiple males and females. Mating may occur year round in locations where the environmental conditions are sufficient. Adult females are able to reproduce at 3-5 months old, can produce up to five litters each year with about 5-8 young in each litter. Adult roof rats usually live about one year.
Norway rats are also polygamous and form colonies of many males and females. Mating generally peaks in the warmer months of the year, but may occur year round in some areas. Female adults will produce about seven litters per year and will mate again about 18 hours after giving birth to her litter of about eight pups. The reproductive potential of one female Norway rat is about 50-60 young per year.
Rats can carry dangerous diseases including leptospirosis, hantavirus, and LCMV.
Depending on the species, rats will typically eat any type of food that is available to them.
Rat fleas feed on rodents and are carriers of dangerous diseases, including the bubonic plague.
Rats will dig holes and gnaw through walls in search of food and shelter.
The most common rats in North America are the roof rat and the Norway rat.
If you've seen one rat, a large-scale rat infestation likely already exists.
Rats usually like to live around humans while muskrats are typically found in wetland environments.
Rats have two smell organs that allow them to smell pheromones.
Rats have two large front teeth, run on four legs, and have tails and ears that vary in size depending on the species.
Although humans are rats' biggest predators, they're also threatened by domestic cats, birds, and snakes.
Commercially available rodent repellents have not been found to be effective at repelling rats.
Although typically not effective since rats are fearful of new objects, rat traps can be baited with food to attract rodents.
Glue traps, snap traps, and zapper stations are common rat traps.
The best way to naturally repel rats is to dispose of food scraps and garbage properly.
If you find a dead rat, contact an Orkin Pro for proper disposal instructions and to identify whether a rat infestation exists.
Rats are attracted to food and can often be found in kitchens.
Find our if there are any sprays that can kill rats.
Find out if rat pellets and traps are effective in killing rats.
Rats can chew through walls and get into homes to cause more damage.
Learn about brodifacoum and warfarin and their effects on rodents.