Types of Rodents: Identifying Common Pests in Tennessee Homes

Common Types of Rodents in Tennessee

Tennessee homes and businesses typically encounter four main rodent species. Each has distinct characteristics that help with identification and inform the most effective control methods.

House Mice

House mice are among the most common rodents found in Tennessee properties. Originally from Asia, they were transported to America in the mid-15th century and have since adapted perfectly to living alongside humans.

Identifying Features:

• Small size (about 6-7 inches long including tail)
• Dark-gray fur on backs with lighter fur on bellies
• Weigh approximately 1 ounce
• Very large ears relative to body size
• Naked tail roughly equal to body length

House mice can spend their entire lives inside a single building, never venturing outdoors. They create nests near food sources and in warm areas such as closets, wall voids, and even bookshelves. These rodents establish familiar territory and travel paths, typically moving along walls and flat surfaces as they forage for food.

Deer Mice

Deer mice are another common rodent species found throughout Tennessee. The two most common varieties are white-footed deer mice and cotton deer mice, which appear nearly identical to the untrained eye.

Identifying Features:

• Medium size (5 to 8 inches long including tail)
• Brown or dark-colored fur with distinctive white feet and undersides
• Large eyes relative to their body size
• More prominent ears than house mice

Unlike house mice, deer mice typically live outdoors during warmer months, taking shelter near trees, logs, rocks, or leaf litter. They hunt for insects, nuts, seeds, and berries when weather permits. However, as temperatures drop in winter, they often seek shelter in homes, garages, or outbuildings. Deer mice may carry serious diseases such as hantavirus and Lyme disease, making their presence a significant health concern.

Norway Rats

Also known as house rats or sewer rats, Norway rats originated in Mongolia and arrived in the United States in the 1700s. Today, they represent the most common rat species nationwide.

Identifying Features:

• Large, stocky body weighing up to 1 pound
• Blunt nose and small ears
• Scaly tail shorter than body length
• Brown to grayish coloration

A simple identification trick: if you pull the rat’s tail over its head and it doesn’t reach past the ears, you’re looking at a Norway rat. These rodents typically live in colonies, creating burrows in the ground, including under buildings in crawlspaces and basements. In urban environments, they often inhabit lower levels of structures, while in rural settings, they may occupy farm buildings and silos. Norway rats are omnivorous scavengers that can survive on virtually any available food source.

Roof Rats

Roof rats originated in Asia and were introduced to Florida in the 1500s before spreading throughout the United States. They remain primarily prevalent in southern states like Tennessee.

Identifying Features:

• Slender body 6 to 8 inches long
• Tail notably longer than body
• Black or dark-gray coloration with white bellies
• Weigh approximately half a pound
• More agile climbers than Norway rats

Unlike Norway rats, roof rats prefer elevated locations, often nesting in attics, roof lines, and even in trees. They frequently travel along utility lines to access buildings. Roof rats are somewhat unique among rodents as they don’t naturally prefer human food, though they will consume it when available. These rodents are extremely skittish and will typically abandon their nests if disturbed.