Exploring Different Types of Rats
Many homeowners are surprised to learn that there are more than 50 different subspecies of rats, each with its own characteristics and traits. If you experience an occasional rat sighting in or near your home, you’re most likely dealing with one of the following four types: ship rats, marsh rice rats, Norway rats, or woodrats.
Here we explore a bit about the most common types of rats to help you better understand these surprisingly complex animals.
Ship rat (aka black rat or roof rat)
Ship rats are usually about 5 to 7 inches long, with a tail that measures up to 8 inches. They can weigh up to half a pound. Despite being known as black rats, they can also be medium or light brown in color and have a lighter underside. Their fur is usually scraggly.
Ship rats got their name because they arrived on trade ships in the U.K. during Roman times from India. Ship rats are found on all continents but are most common in coastal areas and tropical climates. However, they can also adapt to more extreme cold.
Ship rats are omnivores, so they eat a wide variety of foods, including seeds, fruit, stems, leaves, insects, and small animals such as birds. They’re especially drawn to food left out for dogs and cats.
Ship rats and their parasites are known to carry a variety of serious diseases, including the bubonic plague (via the rat flea), typhus, Weil’s disease, toxoplasmosis, and trichinosis.
Marsh rice rat
Marsh rice rats are medium-sized, with a total length of up to 12 inches. Although their coloring can vary depending on their location, many look a lot like ship rats and Norway rats. However, marsh rice rats have greater differences in color between their bodies, heads, and stomachs. The upper body is usually gray to grayish brown, with the head a bit lighter, and the underbelly and feet are often off-white. They have small cheek pouches, and their ears have a patch of light hair in front of them.
Marsh rats are true to their name, appearing most frequently in wet, marshy areas such as the Florida Keys and the Gulf Coast. Their natural habitats range from the eastern United States to Texas and into South America.
The marsh rice rat is omnivorous, eating equal parts plant and animal matter. They love green vegetation, fungus, rice, and marsh grasses, as well as insects, snails, fish, and even fiddler crabs.
Marsh rice rats are the primary host for the Bayou virus, which is the second-most common agent of hantavirus infections in the U.S.9 They also may carry Lyme disease and a bacteria called Bartonella, which can cause several diseases in humans.
Norway rat (aka brown rat)
Norway rats are larger than most other types of rats, ranging anywhere from 15 to 20 inches total, including the tail. They can weigh twice as much as a black rat and many more times than a house mouse. They have coarse, brown or dark gray fur, and their underside is lighter gray or brown.
Although Norway rats originated in Europe, they have spread across the globe. They are very adaptable to different climates because they construct their nests in below-ground burrows or at ground level. They are very good swimmers, so you might even spot them near waterways and pools. They are found throughout the United States, particularly in the Northeast, Midwest, and Southwest, especially in urban areas with multiple food sources.
Norway rats are also omnivorous and will eat nearly anything they can get their paws on. This includes small birds, eggs, all types of plants and small invertebrates.
This species is known for being a carrier of the parasite that causes toxoplasmosis, a disease that results in muscle pain, fever, and headaches in humans. In fact, the parasite has a long history with the Norway rat. Interestingly, research indicates that the parasite evolved to make an infected rat less fearful of cats, making it more susceptible to predation and increasing the likelihood of transmission.10
Woodrat (aka packrat)
Often compared to deer mice, harvest mice, and grasshopper mice Woodrats actually have a distinctively rat-like appearance, with a long tail, large ears and big black eyes. Their size varies depending on their location. For example, bushy-tailed woodrats in desert areas are known to be much larger than their counterparts in mountainous areas.
Woodrats are only found in North America, but they thrive in nearly every climate that the continent has to offer. Bushy- tailed woodrats are common in western North America, ranging from arctic Canada to the deserts of Arizona and New Mexico. In the Eastern part of the U.S., other woodrat species live in the mountains, above the timberline and even in cliffs.
Woodrats are omnivorous, so they enjoy everything: seeds, nuts, leaves, berries, twigs, insects, birds, small mammals, and more.
Woodrats have been found to carry a variety of diseases that are harmful to humans, including Arenavirus, hantavirus, typhoid, trichinosis, and the bubonic plague. They can also carry dangerous bacteria such as salmonella and parasites.