How Many Babies Do Mice Have?

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Mice can get out of control. They’re one of the most invasive mammals in the world, and have transformed themselves into a consistent household pest throughout the entirety of North America. They can reproduce quickly, mate virtually any time of the year, and they grow at an incredible rate. Half a dozen mice can become six dozen mice in a span of just a few months, and they can devastate your home. 

The common house mouse is just a little too good at reproduction. The only way to stop mice from spreading is by calling a professional exterminator, especially if you suspect that you might have the beginnings of an infestation on your hands. Mice can cause a lot of problems, and delaying their treatment can compound the issue to absurd degrees. If you see clear signs of a mouse infestation, call Hama Pest Control.

How Many Babies Do Mice Have?

A single female mouse can produce 5 to 10 litters each year, with their litters consisting of 6 young on average, which can breed within just 30 days of being born.

The Reproduction Cycle of Mice

Mice reproduce very quickly, with the average species of mouse able to breed in just 6 weeks of being born. They also have no specific breeding season, and will have their litters all year if they have proper nutrients and shelter. Males and females can both mate within their first 50 days of being alive, though it can happen much earlier.

The average mating cycle for a female mouse lasts around 5 days, though it can change depending on their hormones and sexual maturity.  Mice make ultrasonic calls to one another that lets males signal the females. Male mice make their courting calls when they smell a female’s pheromones, and will chirp at one another in different tones that can be obnoxious and agonizing.  

Females are pregnant for around 20 days, and can give birth to between 3-14 offspring. This means that a small mouse population can grow substantially within the comforts of your home or business, especially if the mice have access to clean water, steady food, and a warm place to sleep.

Mice Have Babies All Year Long

Since mice don’t have what are considered “seasonal” pregnancies, they can give birth whenever they have available food and shelter, especially when the weather is nice. However if a mouse has access to the indoors, they can give steady birth all year long and become incredible pests. Since the females can mate at just 6 weeks, they can give birth to their first litter very quickly, having 5 or 6 babies per litter. 

Seasons Affect Litter Size

Most species of mice are productive all year long, though some might continue to have the hereditary characteristics of field mice, giving birth to their offspring in the warmer months and holding off for the colder. There are seasonal lulls in birthing mice, and both litter size and gestation length for pregnancies can change depending on the season. 

Mice detect the changing of seasons based on humidity. Even in a controlled environment (such as a home or office) mice can detect minute changes in humidity levels, which affects their breeding frequency and litter size. Though under the safety of the indoors, they might give birth to the same size of litter all year long no matter what.

How Many Babies Do Mice Have According to Breed?

There are many different types of mice that can affect your home, such as deer mice, field mice, or house mice. Different breeds of mice can produce remarkably different litters, both in amount and in frequency, and the type of mouse that’s invaded your home can make your problem range from frustrating to devastating.

Field mice have 2 to 4 litters per year, with the average litter containing 4 to 6 babies. House mice can have an astounding 7 to 8 litters per year, with their average litter containing between 4 and 16 offspring. Deer mice breed all year longer similar to house mice, and their litters can contain upward of 11 offspring. 

How Many Babies Do Mice Have In Their Lifespan?

Since the average mouse that might invade your home can have upward of 8 litters a year and an average of 5-6 babies per litter, a single mouse might produce 3 or 4 dozen additional mice per lifespan. This means that dealing with an infestation as soon as possible is of the utmost importance—if you let mice stay in your home and breed, the infestation will get out of control and before long you’ll have a problem on your hands that’s well beyond simple math.


The only way to deal with a mice infestation and stop mice from having a baby explosion is to call the professionals. Hama Pest Control have decades of rodent experience in Toronto, and we know how to be both preventative and proactive when it comes to mice. While small and cute, mice are devastating and troublesome and should be dealt with using the utmost care. It is best to get rid of mice before they breed inside your home. We always take care of pest problems with the highest ethical and environmental standards, and we are only a phone call away!

Jake Garza
Jake Garza
Jake is the founder of Hama Pest Control, the preferred choice for pest removal and extermination in the Greater Toronto Area. With over thirty years of experience, Jake prides himself in bringing quality, knowledge, and care to Hama Pest Control's customers.
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