The Differences Between Mice And Rats

Identifying Colorado's Most Common Rodents

Mice and rats are pretty much the same, right? They are both rodents. And since they are rodents, they both have a pair of incisors that never stop growing--which is why they never stop chewing and being destructive if they get into homes and businesses. But mice and rats are also very different. In this article, we will explore how rats and mice are different in size, fur, weight, tail length, dropping characteristics, diet, lifespan, breeding habits, and the damages they cause.

Size Difference

Most people are easily able to tell the difference between a rat and a mouse if they see one just by the size of the animal. However, when looking at a young rat, or a large mouse, it might not be so easy. But in general, mice are considerably smaller than rats, measuring around 12 to 20 cm, while rats are about 40 cm. A mouse's head is also much smaller than a rat's head in direct relationship to its body. Rat heads are heavy, blunt and chunky, while mouse heads are tiny, sharply triangular, and have pointed noses. And rat ears are smaller than mouse ears relative to the size of their heads.

Fur & Weight Differences

Mice tend to have softer fur, while rats' fur is more coarse. A house mouse's fur is light brown or gray to black in color, with lighter bellies. A Norway rat has coarse brown fur with a lighter underside.

Mice are not only shorter than rats, they also, logically, weigh less. Mice weigh 30 to 90 grams while rats are between 350 to 650 grams. If you see a rodent that looks like it needs to cut back on the sweets, you are probably looking at a rat, as they tend to look fatter than mice.

Mouse Droppings Vs. Rat Droppings

The droppings of rats and mice are similar in shape but, logically, rat droppings are larger than mouse droppings, and they tend to have more rounded ends. Mouse droppings are more pointed. The droppings left my mice are typically around 4 to 7mm long, while rat droppings measure in at 7 to 19mm. Both are dark in color. If the droppings you see are moist, this means they are fresh. If they are dry or powdery, they have been there awhile.

What They Eat & How Long They Live

Though both of these critters are omnivores, mice and rats usually prefer different foods. Mice tend to eat grains, vegetables, fruits, nuts, and seeds, but they will also eat meat. In fact, mice are known to eat the dead bodies of other mice and even their own tails if they get hungry enough! Rats tend to eat larger items such as stored meats, cheeses, and dry pet food.

Mice live between 1.5 and 2.5 years, while rats typically live 2 to 3 years.

Reproduction Efforts 

A female mouse can produce more than 300 offspring in her lifetime, with those offspring being able to mate in as early as 4 weeks. This means one mouse in a building can quickly become a big problem. Similarly, a pair of rats can turn into as many as 2,000 rats in one year. And, it is worth noting that mice and rats don't mate with each other.

Damages Caused By Mice & Rats 

Mice and rats can both do a lot of damage to a structure, and to belongings, but since rats are bigger, they tend to do more damage in a shorter period of time. They can chew larger holes and chew through things that mice cannot, such as aluminum, brick, wire mesh, and even cinder blocks and concrete! And, since rats chew bigger holes, if those holes are in insulation, walls or roof areas, you'll have more heat loss and more money going out your windows. Rats and mice can both chew through electrical wires, and this can pose a serious fire hazard.

Contact EnviroPest For Rodent Control In Colorado

If you need help eliminating mice and/or rats from your Colorado home or business, contact EnviroPest today! Serving Denver, Boulder, Colorado Springs, and NoCo, our highly trained pest specialists are ready to help you take back your property from these nuisance and destructive rodents. 

View Home Pest Control Services 


Related Rodent Articles