Mice vs. Rats: everything you need to know

Most of us probably can identify a full-grown rat versus a mouse. Easy right? 

It gets a bit trickier to spot a rodent infestation when you don’t actually see the animal but instead only see signs of the problem in or around your home, or in other structures on your property. Additionally, a small rat can look just like a mouse.

In this article, we provide you with everything you need to know about mice vs. rats and rodent infestation. 

Let’s get started by reviewing what mice and rats look like along with other behavioral differences between the two rodent species.

WHAT DO MICE AND RATS LOOK LIKE?

To start, mice and rats are both short-haired rodents but do have different physical traits. For instance, mice are completely covered in fur, while rats' ears and tails are hairless. 

Both animals have stomachs that are lighter in color than the rest of the body, which can be black, grey, or brown. 

Mice often grow to six or eight inches in length. Their fur can range in color from black to grey to brown on their heads, ears, bodies, and tails. 

Their stomachs will always be of a lighter shade. By adulthood, the average mouse will weigh between 10 and 30 grams.

Rats, on the other hand, only have fur on their bodies—their tails and ears are hairless. As with mice, rats’ coloration widely ranges black to grey, with their bellies always being a lighter white. 

At the time of maturation, a male rat will have an average weight of four-fifths of a pound, and a length of nine to eleven inches. or more.

Below is a comparison table of mice and rats, for quick reference.

WHAT ARE THE HEALTH HAZARDS TO HUMANS CAUSED BY MICE AND RATS?

Besides being a nuisance to deal with, rodents can, directly and indirectly, spread over 35 diseases to humans.

Below is the list of the most common diseases rodents spread to humans:

Other diseases that are spread directly or indirectly to human from rodents include Leptospirosis, Lassa Fever and many more. 

WHAT KIND OF DAMAGE CAN RODENTS DO TO YOUR HOME?

You might not think that such a small mammal can do serious damage to your home, but rodents can cause significant destruction because of their chewing and nesting traits.

The following are some of the potential damages rats and mice can cause in your home, garage, or in other property structures:

• Electrical wire damage: chewing, a common rodent trait, can strip the outer insulation and expose wires, which increases the risk of house fires
  
• Structural damage: chewing, to create entry points into your home, through sheetrock, brick, wood, and other materials even roof materials
  
• HVAC damage: chewing in A/C units, ductwork and air returns can introduce airborne rodent diseases into your home
  
• Insulation damage: again, chewing wall, attic, or crawl space insulation can affect insulation efficiency resulting in higher heating or cooling bills or costly replacements of material
  

Note: be sure to check your homeowners (or renters) insurance policy to see if you are covered for rodent damage – each state has different insurance regulations on rodent infestation coverage.

So, what are some other factors you might want to know about mice and rats?

Let’s go over a few we think may help you understand these creatures better.

What do mice and rats eat?

Both mice and rats are omnivorous, meaning that they can eat both meat and vegetation. In practice, this dietary freedom results in frequent consumption of fruits and grains.

In the case of rats, they may also consume small bugs and animals. As all these are often found in gardens and farms, mice and rats are typically drawn to these areas.

How long do mice and rats live?

Outside of domestication, it is not common for mice to live longer than 18 months. When kept as pets, however, a lifespan of roughly two years should be expected. 

In a laboratory setting, mice have been known to live as long as three to five years.

In the wild, 95% of black rats do not survive their first year. If they do, however, female rats generally hit menopause at 18 months and can expect to live no longer than 2 years.

 In a domestic setting, however, rats can typically enjoy a two- to three-year lifespan.

How often do mice and rats breed?

Mice become sexually active six weeks after birth. The gestation period for pregnant mice is three weeks.

Each litter can range between three and fifteen young mice. On average, a female will give birth between five and ten times annually.

Rats have a similar breeding cycle, with sexual maturity arriving at five weeks, a gestation period of 21 days, a range of seven to fourteen rats in each litter, and an average of five pregnancies per year.

Where do mice and rats live?

Being small and omnivorous, mice can live anywhere. When in the wild, mice will typically burrow underground in order to protect against overhead predators.

This can be done either in forests or grasslands. In the case of rats, they may also settle in elevated locations, such as in trees or rafters.

In manmade structures, mice and rats will find anywhere that’s protected, but within close proximity to a food or water source. In a home, this can include walls, cabinets, boxes and crawl spaces, and anywhere near the kitchen.

What are the signs of mice and rats?

There are certain telltale signs of mice and rat infestation. The following are great examples of this:

• Feces. Mouse droppings are black, pointed on both ends, and rod-shaped. Rat droppings are brown, bulging in the center, and rounded on the ends.
  
• Scratching noises from within the walls.
  
• Trails of footprints in dusty areas
  
• Grease marks along tight areas where the mice are frequently active.
  
• The presence of a nest
  
• A strong urine smell where the mice are most active
• Bite marks on food packaging
  

How to keep mice and rats away

There are steps you can take to prevent rodents from entering and nesting in your home. Here are some of the most common things you can do to protect your family and home from an infestation:

• Keep food in your kitchen in sealed containers with tight-fitting lids
  
• Have a tight lid on your indoor and outdoor garbage bins and cans
  
• Clean up food and water sources in your home as well as on the outside perimeter of your house and other property structures
  
• Remove piles of leaves and other yard waste to eliminate any nesting material sources or locations
  
• Look for entry holes inside and outside of your home then plug them with steel wool or with other patching materials
  

By the time the signs of a mouse or rat infestation become visible, chances are that it’s already become serious. In this case, we highly recommend you hire a pest control service.

How to get rid of mice and rats

You can attempt to deal with the infestation yourself by setting traps. The most common type of mousetrap, snap traps, can be used as well as poison traps.

Depending on the severity of the infestation in question, there are differing methods of resolution.

 In minor cases, do-it-yourself methods are the cheaper and logical option. Examples of these methods include:

• Natural sprays to ward off rodents
  
• Bait & poison traps, though this could put young family members at risk
  
• Snap traps, which kill instantly
  
• Cage traps, which leave the mouse or rat alive
  
• Glue traps, though these are considered highly inhumane.

Generally speaking, professional exterminators will employ these same traps and tactics. In the most critical of situations, fumigation may be warranted. 

Should their professional perspective be needed, our top 10 pest control specialists would be more than happy to assist.