Rat vs Mouse: What Are The Differences?

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If you spot a rodent running through your home, you probably don’t care if it’s a rat or a mouse – you just want it gone! However, understanding the difference between mice and rats plays a vital role in pest control.  

Mice are smaller than rats, with better agility and a bolder nature. Rats are larger, stronger, and have increased chewing ability. Black rats live in roof eaves and trees, while brown rats can be found at ground level in burrows. Mice live in burrows but can also move into attics.

What Do Mice Look Like?

When comparing a rat vs. a mouse, the most obvious difference is size. Mice are the smaller of the two rodents. The average house mouse ranges from three to four inches long, with tails between two to four inches.

Adult mice have larger ears but smaller feet and heads compared to rats. Additionally, mice have longer tails than rats (proportional to their bodies, not necessarily in actual size). They’re usually brown or light gray, with paler underbellies.

What Do Rats Look Like?

The two most common species of rats are the brown rat and the black rat. Compared to mice, both types of rats are larger and darker. They range between five and ten inches long with tails between five and nine inches.

Brown Rats

The brown rat has a thick, tubular body shape with small ears and feet (compared to black rats). Their tail is shorter than the combined length of their body and head.

Black Rats

The black rat has a more arched, hunched appearance. Their large, thin ears are hard to miss, along with their big, hairless feet. Unlike brown rats, black rats have tails that are longer than their bodies.

Where Do Rats and Mice Live?

Mice, brown rats, and black rats all have individual preferences about where they like to live.

Brown rats are mainly ground-based. They’ll live both indoors and outdoors, often creating elaborate rat burrows. Brown rats also travel through sewer systems with ease.

Where Do Black Rats Live?

Black rats spend their time in high spaces, such as under roofs and in trees. They have no issue scaling great heights and accessing out-of-the-way areas. Additionally, they have a long history of living in ports and on ships, which is why they’re also called “ship rats.”

Where Do Mice Live?

Mice nest in burrows. While they usually live at ground level, they’re also excellent climbers and can find their way into attics and similar spaces.

Are There Differences in Droppings?

Another important factor when comparing a rat vs. a mouse is the shape of their droppings. Mice droppings are between one and two millimeters in length. They’re black, grain-shaped, and typically plentiful, as mice produce approximately 80 droppings per day.

Brown rat droppings are grain-shaped, but much larger, between 10 and 20 millimeters. Each dropping has a tapered end. Brown rats make about 40 droppings daily.  

Black rat droppings are longer, thinner, and slightly smaller than brown rat droppings. The droppings have a curved, banana-like shape with tapering on both ends.

Rat Behavior vs. Mouse Behavior – Is There a Difference?

How do you know if you have rats vs. mice? Where you see the rodent and what it’s doing can provide important clues. 

Mice are small but bold. They’ll explore a structure from top to bottom, searching for food, nesting, and other creature comforts. Due to their size, they have no problem squeezing along pipes, traveling within walls, and fitting in other small spaces.

Rats are far more cautious – even fearful. While they don’t have the same ability to squeeze through tight spots the way mice do, rats are more vigorous chewers, so they can move through a structure by destroying it.

Who Causes More Damage?

Both can cause extensive damage to a structure. Although mice aren’t as strong as rats, they can still chew through walls and electrical wires, creating a fire hazard.

Rats have fewer limits on what they’re capable of chewing through. They can destroy wood, sheet metal, glass, and even concrete.

Are Rats Worse Than Mice?

While both animals can create extensive damage and cause health problems, rats are arguably worse than mice. Because they’re bigger and stronger, they can cause more damage in a shorter time than mice.

Of course, just because mice are small doesn’t mean they’re harmless. They have an easier time traveling through structures than rats. Mice can remain undetected for long periods, causing extensive damage before anyone notices.  

How Do You Prevent Rats and Mice?

You want to block access to the inside of your home while removing enticements like food and water.

Keep woodpiles away from the side of your house. Also, trim down all external vegetation. The less time rodents spend around the perimeter of your house, the less likely they are to find ways to enter. If any doors or windows have a gap larger than a pencil, both mice and rats can slip inside.

Seal your garbage tightly and place it in a closed, metal container. Try to avoid leaving garbage cans outside when full for long periods. Every once in a while, clean your garbage cans with a bleach solution.

The best way to prevent mice and rat infestations is with the help of professional pest control services. A trained exterminator can identify entry points and develop custom solutions to keep mice away.  

Can Rodents Cause Health Problems?

Rats and mice infestations can result in a vast host of different health problems for humans, including the following:

  • Salmonellosis
  • Hantavirus pulmonary syndrome
  • Plague
  • Hemorrhagic fever with renal syndrome
  • Lassa fever
  • Leptospirosis
  • Rat-bite fever

Diseases are transmitted directly, through bites and other physical contact, and indirectly through bacteria spread when rodents walk across household surfaces.

When comparing a rat vs. a mouse regarding health risk, both pose potentially serious problems. 


While mice and rats have a lot in common, there are also significant differences in their size, dropping shape, behaviors, and more. Understanding these differences allows you to predict their actions and prevent an infestation. With the help of rat and mice pest control professionals, you can reclaim your home from these troublesome invaders.

Jake Garza
Jake Garza
Jake is the founder of Hama Pest Control, the preferred choice for pest removal and extermination in the Greater Toronto Area. With over thirty years of experience, Jake prides himself in bringing quality, knowledge, and care to Hama Pest Control's customers.
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