30 Commonly Asked Questions and Facts About House Mice

House mice are one of the most common animals in the world, and are found everywhere that humans live. As their name suggests, they’re extremely common in our homes, and generally prefer to live in houses than out in the wild. Since they’re such common pests, people tend to have lots of questions about them. If you have questions about house mice, there’s a good chance someone else has already asked the same question. These are the most common questions about house mice.

1. Is it common to have mice in your house?

Yes, it’s quite common. Estimates vary, but some think that as many as 21 million homes are infested with mice every year in the United States. Mice are very common animals. They breed quickly, can live in almost any climate, and they eat a lot of the same foods we do.

That means that mice tend to live in all the same places we do, and our homes are very attractive places for them. Especially in the winter when houses are warmer and safer than the environment outside, mice are drawn to houses like a moth to flame.

2. Why do I have mice in my house?

Mice want the same things every animal wants: food, water, and shelter. Your house happens to provide all three. Mice are far from the only animals that would love to take up residence in your house, but they’re one of the few species that’s small enough and adaptable enough to actually do it. Having mice doesn’t mean your home is dirty, it just means they found a way in.

3. If you see one mouse how many do you have?

It’s difficult to answer this with precision, because there’s just no way to tell how many mice you have without capturing or killing them all and counting. If you saw the mouse during the day, and in a heavily trafficked area of your home (such as the kitchen), there’s a good chance it’s alone. Mice are rarely active during the day, so this one was probably pressured into your home by weather or predators.

If you saw the mouse at night, especially in places like the attic or a closet, you almost certainly have more than one. Exactly how many there is nearly impossible to determine, but you’ll want to take steps to remove them immediately.

4. Does one mouse mean an infestation?

One mouse is not considered an infestation. However, one mouse can lead to an infestation very quickly. Mice breed quickly – a single female can have 5-10 litters per year (if they’re living inside a house, it’s closer to 10), each averaging 6-8 young, and each newborn female will reach breeding age six weeks after they’re born. You might only have one mouse now, but it likely won’t stay that way for long.

5. What are the odds of only having one mouse?

They’re not great. We can’t give you exact odds here – sorry, but the numbers just aren’t precise enough for that. What we can tell you is that if you see one mouse, it’s unlikely that it’s alone. We’ve outlined one (and pretty much the only) scenario in which you might only have one mouse: a mouse that’s been pressured into your home by bad weather or predators.

If that’s the case, you’ll likely see the mouse during the day in heavily trafficked areas of your home. More often than not, if you see a mouse, it’s just one of many.

6. Do mice leave on their own?

Mice won’t leave on their own. Your house is a perfect habitat for them. There’s plenty of food and they barely have to work for it. It’s warm and dry all year long. There are no predators trying to eat them. There’s no reason for them to leave. You’re going to have to give them some encouragement. In fact, your house is so great to them that, even if you capture one and release it outside, it’s just going to go straight back in.

7. How do you know when all the mice are gone?

When all the mice are gone, you’ll stop seeing signs of a mouse infestation. Mouse droppings will no longer pile up, there won’t be any more damage to places where they were chewing, no more smells from their urine, and no more sounds from mice scrabbling around inside your walls.

Determining that mice are gone will take some effort. It’s not enough to simply observe the absence of these signs in your living room and kitchen, you need to go into places like your attic and other rarely visited parts of the home to make sure they’re really gone.

8. Do mice usually go upstairs?

Anyone who’s kept a pet mouse can tell you that mice are excellent climbers. They can very easily climb up a set of stairs, or climb out the outside of the house or inside the walls and access the second floor that way.

In fact, your attic is probably one of the most attractive spaces in the house to a mouse. It’s dark, quiet, and people rarely go up there. Mice gravitate towards spaces like that.

9. Why do mice come in the house in the summer?

Winter mouse infestations are common because the mice are seeking a warm place to get out of the cold. People are often told that mice will leave their houses in the summer, but summer mouse infestations are still common. What gives?

Your house is cool in summer, just like it’s warm in winter. It’s still full of food and water and provides excellent shelter. In other words, mice come into your house in summer for the same reason they do in winter- living conditions inside your house are better than they are outside your house.

10. Do mice leave the house in summer?

This is a commonly held belief, and it may not be entirely false. Houses in climates that have harsh winters and mild summers may indeed experience mouse infestations that disappear of their own volition in the summer.

In most places, though, once the mice are in your house, they’re there to stay until you forcibly remove them. You should never count on mice leaving on their own.

11. What time of year do mice come in the house?

Mice can and will come into your house at any time of year, but there is a definite “rodent season” when this is much more likely to happen. As the weather starts to grow cooler, mice and other rodents begin searching for a warm, comfortable place to spend the winter. Since they don’t hibernate, they’ll need food nearby, too. Your house fits the bill.

It will depend on what part of the country you live in, but generally this starts happening sometime between August and October in the United States. By November most of the mice have hunkered down and you’re less likely to get a new infestation.

12. Where do mice hide?

Where you’re least likely to find them. Mice avoid humans as much as possible, and they’re pretty good at it. They’ll build their nests in the areas of your home that you visit the least. Voids in the wall are especially popular, as are attics and the insulation in the walls.

They’ll also hide underneath your kitchen appliances (fridge, stove, dishwasher, etc). Even a drawer or cabinet you don’t open very often can hide mice. Essentially, any place in your home that’s dark and that you don’t or can’t access frequently is a prime hiding spot.

13. How do you make a mouse come out of hiding?

To make a mouse come out of hiding, you need smells. You can use smells that smell so good to them they can’t resist, or smells that are so foul to them that they just can’t stand it.

While you might thinking cheese is the best mouse-bait, you’d be wrong. Research has shown that mice actually aren’t all that attracted to cheese, preferring foods higher in carbohydrates. If you want to draw them out, peanuts and peanut butter work well. If you want to drive them out with unpleasant smells, peppermint, cayenne pepper, and cloves are all said to repel mice.

14. How do you keep mice out of your house in the winter?

You could try using the aforementioned bad smells (bad to mice – most people like them), but while that can help drive them out of hiding it may not be the best solution to preventing them from entering your house. Using essential oils to repel mice has worked for many people. The first and best step you can take is to seal your house up tight.

Inspect the outside of your house for cracks and gaps that a mouse could slip through, and put mesh covers on all vents. Make sure windows and doors are sealed tight. Then take a look inside at the sorts of places mice like to hide. Remove clutter and trash from these places and make sure that any food in your pantry is sealed in airtight containers.

15. Are mice and rats the same?

While mice and rats are both rodents and they share many characteristics, they are entirely different species. The first and clearest difference is that rats are typically much larger than mice. The average house mouse weighs less than two ounces, with a three to four inch body. Rats can weigh as much as 17 ounces with a length of 11 inches.

Rats are typically more cautious than mice, but they’ll often inhabit the same types of places and eat many of the same foods, although rats eat meat more readily than mice. In fact, rats have been known to hunt and eat mice!

16. Do mice turn into rats?

No, mice do not turn into rats. Rats are an entirely separate species. While they have similar body shapes and even similar coloration, they aren’t even considered to be closely related species. Mice will often avoid rats, as rats sometimes eat mice. If you think you’ve seen both mice and rats in your home, it’s possible that what you’ve actually seen are both juvenile and full-grown rats.

17. How long does it take a mouse to chew through a wall?

That depends on what the wall is made of, why the mouse is chewing through it, and how many mice are chewing in the same spot. Like most rodents, mice need to chew things to keep their teeth from growing too long and to keep them sharp. So, sometimes a mouse is chewing just to chew. Other times their trying to access water or food, or create a hole to travel through. They’ll chew much faster in these latter cases.

A wooden or plywood wall won’t stop them for long. A thicker wooden wall may take them a few days or weeks. If you notice that mice are gnawing on your wall, tape steel wool to the spot they’re chewing on to dissuade them.

18. How long does it take a rat to chew through a wall?

Just like with mice, this depends on many variables. A rat can certainly chew through a wall much faster than a mouse, but the rate at which they chew will depend on what and why they’re chewing. A typical wooden wall may last for a few hours or a couple of days with a rat trying to chew its way through.

19. What’s the most humane way to get rid of mice?

By far the most humane way to get rid of mice is to use non-lethal, catch and release traps. These traps safely and effectively catch the mice and allow you to take them somewhere far from your home where you can safely release them. If the infestation is really serious and you have to kill the mice, traditional mousetraps kill them very quickly and they don’t suffer. Using poison or glue traps is not recommended.

20. How do exterminators get rid of mice?

Usually with mouse traps. Most exterminators will focus on killing the mice, rather than relocating them. Relocating them in such a way that they don’t return to your home is very time-consuming, and it’s not a feasible option for most exterminators. They will place a variety of mousetraps in several different locations around your home where they suspect the mice are hiding.

Sometimes they’ll use glue traps – these are very inhumane and cause a lot of undue suffering for the mice that get trapped in them. So if they plan to use glue traps ask them to use traditional mouse traps instead.

21. How much does it cost to get rid of mice?

On average, it costs between $450 and $600 to hire an exterminator to get rid of mice. It’s difficult and time-consuming work, but it’s also easier and cheaper than other pest removal problems. The exact cost will depend on the severity of the infestation, the specific pest removal company you hire, and your location.

Of course if you go the DIY route it will only be the cost of traps, modifications to your home to prevent more from getting in, and your time.

22. How long does it take to get rid of mice?

It will require at least two appointments with the exterminator. One to judge the severity of the infestation and set out traps, and one to verify that the mice are gone. More appointments may be needed in between to set more traps or relocate the traps. Either way, the mice should be gone in less than 90 days.

23. Do house mice carry diseases?

Yes, house mice can carry disease. This is one of the most pressing reasons to have a mouse infestations removed as quickly as possible. While rats are infamous as being the primary carriers of the Bubonic Plague, mice can carry it, too. Leptocyrrhosis, Hantavirus, Hemorrhagic fever, and many other diseases can be transmitted directly from rodents to humans.

There are also diseases that can be passed indirectly from rodents to humans, through fleas and other pests they carry. That list includes Lyme disease and West Nile virus. Mice certainly present a serious threat to your health.

24. What does mouse urine look like?

Mouse urine is difficult to spot under most conditions. It doesn’t even have a strong, urine-like smell to it. Some people say it smells like popcorn to them. The best way to spot mouse urine is with a blacklight. Mouse urine fluoresces under UV light, so while it’s hard to see normally, an inexpensive blacklight will quickly reveal it.

25. Can you smell if you have mice?

Yes, you can. Mice have a strong, ammonia-like smell that’s very similar to the smell of urine (although, oddly, this smell is not caused by their urine). This smell is left by the mice in areas they nest in and along the routes they travel as they forage for food. It helps them to navigate and to tell other mice where to find food. The smell will grow stronger the closer you are to their nest.

26. Will mice leave if they smell a cat?

Mice are terrified of cats. Even a mouse that’s never seen or smelled a cat before will immediately turn and run if it smells cat urine. So, will having cats in your house prevent or end a mouse infestation?

Not necessarily. Cats will definitely keep mice away from places like your kitchen, living room, and bedroom. But mice like to nest in the attic and in the spaces inside your walls, and your cat can’t get to them there. Mice know that, and when they smell your cat they’ll probably just return to the safety of their nest. In short, no, mice won’t leave your house if they smell a cat.

27. Why do I have mice if my house is clean?

Mice aren’t necessarily drawn to dirty houses. Every house offers more or less the same things that mice want: food, water, and shelter. Even a clean house has food in it that mice can eat, and they can access it even if you keep the kitchen and pantry spotless.

No matter how clean your house is, the spaces inside your walls and up in your attic still offer warm, safe places for them to nest. Keeping your house clean does not keep mice away.

28. Is it worse to have mice or rats?

Rats and mice cause many of the same problems. They carry the same diseases, and they both can trigger allergies and asthma. Rats can be more aggressive than mice, especially around their offspring, and they’re more likely to bite you if they feel threatened. Mice are less aggressive, but their smaller size makes it easier for them to sneak around your home unnoticed.

Mice also reproduce faster than rats, so an infestation can get serious much faster. Most people assume rats are worse- they’re larger, more aggressive, and more strongly associated with filth and disease. Rats are usually noticed in the home sooner, and may be slightly easier to get rid of. Mice are probably slightly worse to have, since they can go unnoticed for much longer and reproduce faster.

29. Is it safe to sleep with a mouse in the house?

Yes, you’re in no immediate danger. The biggest danger that mice pose to humans is the diseases they carry. These are often transferred to humans when the mouse bites or when you come across their droppings, neither of which will happen while you sleep.

30. Are house mice dangerous?

House mice can spread dangerous diseases to humans. This is the primary danger, although there is some risk of mice causing dangerous damage to your home by chewing through electrical wires or insulation.

Mice typically don’t bite unless you try to handle them, so you don’t necessarily need to feel afraid of them. You simply need to have them removed before they damage your home or spread disease.

Other than this, you are in no imminent danger from having a mouse, or mice in your house. Many times people live with mice in their house for months or even years without even knowing it. Once you do notice their presence though, it’s best to act quickly and get them out.