Rat vs. Mouse: What’s the Difference?
Rodents first appeared in the fossil record over fifty million years ago. While they are believed to have originated in Asia, they have quickly spread to develop massive populations all around the globe.
Rats and mice hail from a common ancestor. Although they are similar, they have several key differences. Though closely related, rats and mice cannot interbreed with each other, a comforting thought when you’re tackling an infestation.
While rats and mice may seem similar, these common rodents are not identical. On the surface, they may appear similar in both appearance and behavior, but it is important to know the key differences between the two. Unless you know the exact differences between each species, you cannot successfully tackle an infestation.
Difference in Look
Rats are medium-to large-sized rodents with long, narrow tails. There are several types of rats, including kangaroo rats, Norway rats, black rats, wood rats, and many others. While these different species share certain characteristics, they also have differences in habits and preferred behaviors. When people talk about rat infestations, they usually are referring to black rats or Norway rats.
Mice, on the other hand, are smaller, but also sport long, thin tails. Like rats, there are many species of mice that may or may not be closely related to each other. Common types of mice include house mice, field mice, and deer mice. Usually, house mice are the most common offenders in homes.
Mice are white, brown, or gray in color. They can live anywhere in the world in a variety of climates. Rats tend to be black, brown, white, or gray. They tend to be very dirty and will leave grease marks on surfaces. Rats have a somewhat shaggy coat, with some varieties displaying a sleeker, smoother fur.
Norway rats have six pairs of nipples, while house mice have five. Norway rats tend to be heavier at around five hundred grams, while house mice are only about ninety grams. Rats also have longer, eight-inch tails, compared to mice who have four-inch tails at their longest. Mice only grow to about three inches long, while rats can grow up to eleven inches in size. Because of their larger size, Norway rats also have larger ears, feet, heads, and other body parts.
Although you may not want to get up close and personal to spot these particular details, there are a few more differentiation characteristics. Norway rats have chunky, blocky heads, while mice have small, triangular heads. Norway rats have smaller ears.
If you happen to find a nest, you may be unsure of what species you are dealing with. Baby rats have more juvenile proportions and thicker tails than baby mice. The ears on young mice will also look disproportionately large.
If you have an active rodent infestation, you will likely notice droppings around your home. Rat feces tend to be larger than mouse feces. Mouse droppings are shaped like rods, while rat droppings are more spindly. Other telltale signs of mice invasions include gnaw marks and tracks. Rats, like mice, can be detected through their droppings and gnaw marks, as well as pathways and burrows. Rats are nocturnal and have awful eyesight, just like mice.
Behavior
Rats frequently kill mice, called muricide. They hunt and then eat both juvenile and adult mice. To do this, a rat will chase a mouse and bite it in the head, neck, or upper back with its sharp front incisors. The first bite is usually fatal. As a result, rat odors are stressful to mice. You likely will not find an active infestation of both species as mice will vacate or hide if they sense rats in the area.
Mice are nocturnal and very shy. You likely will not see them out in the common areas of your home, but instead hear them running about at night.
However, they are often curious and will take new pathways, unlike rats, which tend to be extremely cautious. They will avoid new situations and obstacles unless they have had time to acclimate. Therefore, if you are setting rat traps, you must make sure you put the traps in an established rat path. Mice, on the other hand, can be trapped just about anywhere, but if you don’t catch anything in a few days, you should take it as a sign that you must move the trap.
If given the choice, mice will prefer to eat grains and plants but will eat anything if they are under duress. Mice tend to build their nests in concealed areas, usually near sources of food. They build their nests of soft materials, such as wool or shredded paper.
Rats will eat just about anything, making them challenging little scavengers to deal with. They prefer meat and grain, and also need about an ounce of fluid every day. They can live in burrows or make nests in walls, attics, or trees.
Rats can also enter into buildings via small openings. They are strong swimmers and can travel through murky areas such as sewers, making them able to enter buildings through broken drains or toilets. They can climb to get to food and follow regular pathways and routines. They usually don’t travel further than three hundred feet from their nests.
Breeding
Both rice and mats breed prolifically. In just one year, a single female mouse can produce up to sixty baby mice in a series of ten litters. Norway rats develop more slowly than house mice, with an average gestation of twenty-two days. House mice, on the other hand, take about twenty days to develop.
Although both species are born hairless and blind, Norway rats are fully furred at fifteen days. Mice are furred at ten days and also open their eyes sooner. Female rats can have six litters of up to twelve individuals per year. Rats can begin to breed at three months old and reproduce primarily in the spring.
Motion Abilities
Mice stand on their hind legs, supporting themselves with their tails. They often stand to figure out their location or to eat. Mice can swim, jump, and climb, even on vertical surfaces. They can jump up to thirteen inches high.
Mice are most active at night, as they don’t like bright lights. They can slip through small spaces, some even wedging their bodies into holes less than half an inch in diameter.
Mice are color blind but have strong senses in hearing, taste, smell, and touch.
Lifespan
Mice can live up to six years. However, in the wild, they tend to live much shorter lives, usually less than a year. Like mice, rats are nocturnal and can be found anywhere in the world. Rats live up to eighteen months.
How to Get Rid of them
Your rodent control efforts will be more effective if you are aware of the exact differences between the two species. For example, small mousetraps that are useful for mice will not work for rats.
Both rats and mice transmit a variety of dangerous diseases. Don’t hesitate to take action once you detect signs of an infestation. Your first line of defense in getting rid of rats and mice is to exclude them. Make sure all doors, windows, vents, chimneys, and openings for utility lines are sealed as well as possible to prevent rodents from entering your home.
Next, you can set snap traps or glue traps. Make sure you select the appropriate sized trap for the specific type of rodent infestation. Mouse traps will be too small for rats, and vice versa. You might also consider putting out mothballs or rat poison. Keep in mind that rat poison can be fatal to animals and humans and it must be kept out of the way.
You should always consider calling an exterminator if your infestation has grown out of hand. While exterminators will conduct similar methods as a homeowner to get rid of an infestation, they are savvier in the differentiating behavior between the two species and can employ more targeted interventions. They are also aware of the best and least invasive pesticides to use, improving the likelihood that you will get rid of your infestation–and fast. Also, both types of rodents are capable of spreading disease to humans.
Rats vs Mice Infographic
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