mouse reproduction cycle

How Often Do Mice Reproduce While Living In My House

How Often Do Mice Reproduce

miceThe house mouse has become the most effective mammalian invasive species on the planet. While they’re not indigenous of North America they have pretty much made themselves a household pest. Their achievement may partially be led for their reproductive capability. Which, in contrast to other mammals is quite rapid. Approximately 6 mice may grow into over 60 mice in a few months. Achieving sexual maturity at about a month old, it’s clear to see what sort of mouse population inside a house can easily grow-out-of-hand. The common house mouse, no matter how cute people think they may be, can have a devastating effect on your house as a pest in a surprisingly short amount of time. This is mainly because the common house mouse is exceptionally efficient at reproduction. Essentially, posting a treatment will only lead to more and more problems. Professional mice pest control by a licensed exterminator can stop them in their often do mice have babies

The combination of year-round breeding, relatively large litter sizes and reaching sexual maturity at a young age means you need to call a licensed exterminator in Toronto immediately you suspect you might have a rodent invasion. Professional extermination is the only way you can guarantee that the critters are removed permanently.

Mice Reproduction

How often do mice have babies? Many people have this question when they see mice in a house. Just one female provides between 5-10 litters annually. Each litter consist of 5-6 young which are able to breed at approximately 30 days-of-age.

How fast do mice reproduce? The single female mouse can give birth 5 – 10 times within one year, so the mouse population can increase very quickly. Mouse gestation period is approximately 20 days so mice create a great number of young (between 6 – 12). Breeding can occur throughout the year and thus if a pair of mice enters your home they can produce hundreds of mice in the short period of time. Mice that live outdoors can live up to 12 months on average. Mice that find a cozy indoor dwelling can live between 2 to 3 years. Unfortunately, mice are well-known breeding machines. During that time they will stay in their nests which are inside wall voids and insulation. They will follow the trails they create towards food and water and will only rarely be visible.

mice in garden

With an average of 5 to 12 young for each litter, it means that this little pest can have as many as seventy baby mice a year. And as if that weren’t enough, the average female mouse can be ready to produce offspring when she is just two months old. To make matters worse, the breeding period is also not restricted to mice breeding throughout the year. This means mice reproduce at an exponential rate and if left unchecked, their populations can reach epidemic proportions in no time at all.

Mouse Breeding (Reproduction) Cycle

Female mice reach a sexually mature age at just 6 weeks old. The fact that mice can get pregnant so young is why they can produce so many babies each year. Once pregnant, it only takes approximately 3 weeks for a female mouse to give birth. Each time she gives birth, her litter will contain roughly 5 or 6 pups, though she may give birth to as many as 12 baby mice at once.

How Many Litters do Mice Have?

Mice can reproduce at a very fast rate and can give birth to a litter of 14 pups at a time with a maximum of up to 5 litters a year. Females can give birth to 100 babies in a year if the problem is left untreated. Mice can breed at an exceptionally fast rate and become sexually mature at just a few weeks old. The issue is not with the breeding itself but how quickly mice mature. Mice have no boundaries when it comes to mating and will easily inter-breed, causing the issue to spiral out of control. The mice in your home may have been around for generations, especially when you have purchased a home in a historic neighborhood. Generations after generations might have been living and dying between the four walls of your home.

Baby mice stay with their mothers for a minimum of 3 weeks. They are virtually deaf and blind when they come into this world. The average life span of a mouse in nature is usually under a year and this is due to several factors. The mouse is a well-sought after prey that is liked by every animal you can imagine. From dogs to snakes, despite all these hurdles, the mouse can find a safe haven in human habitats. You will be surprised to find out that the lifespan of a mouse living inside of a human home is tripled, and this is the reason why it is so hard to move out of the home because there is almost nothing to counter the benefits of a warm home has to offer with plenty of food. Professional pest technicians are therefore needed to make sure that they will no longer be a bother and a menace to your normal way of life.

mice feeding babies

A mouse will nurse her babies for approximately 3 weeks. However, she is capable of breeding again almost immediately after she gives birth. In other words, a female mouse can have another litter of babies approximately 25 days after giving birth to the previous litter. After a year’s time, one mouse can produce several other females capable of breeding.

In fact, her female offspring have likely already given birth to several babies of their own who are also in the process of breeding by the time a year has passed. The cycle can continue like that for a year, or up to a maximum of 3 years, by which point you can have several hundred mice invading your home.

Sadly, mouse breeding cycle is very quick and at just three weeks old, mice are already grown enough that they can damage your home and belongings. They are already old enough to gnaw through food packages or start chewing on insulation, wood, and other items that may seem appealing. Unfortunately, the problem continues to worsen as they grow older and produce more babies of their own.

How Many Mice in a Litter?

Litters range from 3 to 14 mice, with the average sitting between 6 to 8. Also known as pups, baby mice are blind and deaf at birth. They weigh only 1 or 2 grams and are completely hairless. Pups depend entirely on their mothers at birth, feeding on their mothers’ milk and remaining in their nests for about 3 weeks. They begin to grow fur and teeth at one week of age, then open their eyes at 2. At 3 weeks, they are weaned, then at 4, they hit puberty and weigh approximately 10 grams. Mice grow very quickly.

Mice are polygamous and breed year-round. In the wild, they tend to breed more in the spring, when food is more widely available. In homes, they have no trouble breeding all year round. Males usually mate with several females at once, creating communal nursing groups in which one male protects the offspring of several females. Mice are often quiet when their pups are first born, taking care of them around the clock. This often leads people to believe that the mice in their home have left, only to find several more emerging in the following weeks.

House Mouse Behaviour

The house mouse chooses to live in places where they can find both a good supply of food as well as a place where they have good access to moisture or water. Leftover pet food, other food scraps and waste bin bags act like magnets for these pesky little critters. And due to their prolific reproduction abilities, if one female mouse moves into your house, then it means that within four short months you could have over two hundred mice making a mess of your house.

Mouse Built a Nest in Insulation
Mouse Built a Nest in Insulation

And of course, the truth that they are active year round. The incredible birth-rate is kept in check normally by their natural predators in the outdoors. Predators like owls, hawks, cats along with harsh winter and summer conditions can help maintain a rodent population in check. Indoors, however, that is a different story. Once mice find their way indoors they have access to shelter, water and food. They will slowly make their way from one room to another while creating tunnels inside the insulation and behind walls and drywall. They will be virtually undetected until they make their way inside your living area.

The house mouse is not only a threat to your pantry and food stores either. House mice carry pathogens and can transmit deadly diseases like typhus and the bubonic plague. House mice can also be particularly devastating for your linen, furniture and other home furnishings because the house mouse is known for gnawing and burrowing and not even walls are safe from their fierce teeth.

Knowing how prolifically these pests reproduce should make you realize that it can be devastating to ignore one little house mouse, because that mouse could multiply in no time and at all and before you know it, you could have a devastating infestation on your hands.

Health Risks of Mice Breeding in the House


Like all rodents, mice are disease carriers and you might be putting your family at serious risk by ignoring the infestation even for a few days. The more the rodents continue to breed, the higher the chances of infecting humans or pets with one of these diseases;

Leptospirosis: is spread by drinking water or eating food that has been contaminated with urine from an infected rodent. The disease can also spread through contact with broken skin. The disease has a very low mortality rate and is treated with antibiotics. Symptoms include coughing, diarrhea, chills, high fever, headaches and muscle pain.


Hantavirus Pulmonary Syndrome (HPS): some experts believe that the mortality rate for HPS is as high as 36-percent. It is primarily spread by inhaling dust contaminated with infected mouse droppings or urine. The disease can also be contracted through direct contact with the rodent or its droppings or urine. Symptoms include fever, nausea, headaches, body aches, abdominal pain, dry cough and vomiting.

Lymphocytic Choriomeningitis (LCM): like HPS, this disease is also primarily contracted through inhalation of contaminated dust. Mice can carry the virus for their entire life without showing any symptoms while spreading it to humans and pets. The disease is especially dangerous for pregnant women as it can cause serious complications with the unborn baby. Symptoms include malaise, fever, photophobia, anorexia, headaches, nausea and vomiting. LCM also causes meningoencephalitis, aseptic meningitis and encephalitis.

Rat Bite Fever: also known as Haverhill Fever is spread when scratched or bitten by an infected mouse or another rodent. The disease can also be contracted from handling an infected corpse. About 10-percent of rat bites lead to an infection although it is prudent to visit a doctor in case you are bitten or scratched by a mouse. Nearly all wild and domesticated mice carry the bacteria that cause rat bite fever (S. Moniliformis).

Plague: is spread through coming into contact with an infected rodent or by a bite from an infected flea. Despite this being a massive killer in the Middle Ages, the mortality rate for plague currently is lower than 10-percent. The disease is treated with antibiotics while symptoms include weakness, chills, fever, headaches and tender lymph glands.

How Do You Stop Mice From Multiplying?

The best way to not have to deal with mice is to not let them get in in the first place. Limiting their food and water sources will slow down their multiplication rate. But if they are in then the second best way is to get rid of them in rates faster than their reproduction. Mouse traps work, but to get rid of a problem you will need many. By many we mean dozens. You will need to check them daily, empty the dead ones or if you use live to catch the live ones and reset the traps. The best way to deal with a mouse population, however, is to hire The Exterminators. We are licensed exterminators and have access to tools and products that the general public does not. Very potent rodenticide that will stop rodents in their tracks. Our technicians are meticulously trained to provide the highest standard of service. We also solve mouse problems several times a day so experience helps us understand and deal with a mouse problem quickly. Here are some products from our mouse trap section. For guaranteed mouse control services call: 647-496-2211

Notice that most of these diseases are spread via inhalation or coming into direct contact with infected rodents. It is a bad idea to attempt to handle a rodent problem on your own without the proper safety gear, especially in enclosed spaces such as attics, garages and basements. Hire an exterminator with the right safety equipment and best removal methods to guarantee that the rodents leave for good. You can count on The Exterminators Inc. for all your pest control needs.

Updated: July 19th, 2018