How Long Do Pet Mice Live on Average?

pet mouse 3

We want to keep our little furry mouse friend with us until our last days on Earth, sadly because of their lifespans; we must watch them out of this world before we do.

The average mouse lives to be two years old. However, depending on their quality of life and their species, they can live longer.

What is the average lifespan of a mouse?

The average lifespan of a mouse is almost entirely dependent on if the mouse lives indoors within a cage or outdoors in the forest and the fields.

A mouse who lives outdoors in their natural environment can live up to 2 years. However, a mouse that is kept as a pet and left in a cage where they are safe from all of their natural predators and have all of the food and water they need for their entire life usually lives up to three to four years.

Living in nature means that the life of an outdoor mouse is half that of an indoor mouse. When you consider all of the dangerous factors that are in nature which outdoor mice have to deal with, this makes sense. There are far more predators outdoors then there are inside a human’s home. There are also poisonous berries and vegetation that must be avoided and dangerous traps like floods, muds that can suffocate a mouse, forest fires, and insects like spiders and wasps.

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white pet mouse eat seeds

The species of mice and their lifespans

There are many different types of mice in the world. These groups of mice are usually organized as old-world mice and new world mice. These terms were developed because mice that live in Europe, Asia, and Africa are different from those in South and North America. 

Below is a shortlist of mice and their corresponding life spans. These life spans are common for these mice if they live out in the wild. If any of these mice are turned into pets and kept safe with a good diet, you can add them from one year to 18 months on their lifespans. 

  • White foot mice – 2-3 years
  • House mice – 1 year
  • Deer mice – 2 years
  • Western Harvest Mice – less than one year
  • African Pygmy mouse – 2 years
  • Striped Field mouse – 4 years
  • Silky mouse – 2 years

What shortens a mouse’s life?

1. The danger of nature

As we can see from above, living in the wild surrounded by predators severely shortens the lifespan of a mouse. Although many articles are suggesting that humans should allow their mice to run around outside in their backyard or a nearby park or forest, this could be a terrible idea. Mice do not like to be around too many mice, so they don’t usually form colonies. If they did form colonies, it can make life easier as they could learn to provide for each other and take care of newborn pups. But it could also stress out other mice and cause them to attack and pretty trailer. If there are too many mice in one area, they can become territorial and lash out at others.

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2. Cheese

Another reason why a mouse’s life is shortened is because of the quality of their diet. Many mouse owners and caretakers follow dated and dangerous rules regarding providing a healthy and nutritious diet for their mouse. One negative rule that owners follow is feeding their mouse cheese. There are many cartoons, jokes, and idioms revolving around a mouse’s love of cheese. However, this concept is false. Mice don’t particularly love cheese. They would rather eat nuts and fruit instead. Also, cheese can cause a mouse to develop diarrhea and vomiting. Mice are lactose intolerance, so they will have a hard time digesting cheese, and the food will wreak havoc on their digestive system.

3. Low-quality food

Another dining room that owners do not follow is providing their mouths with pellets that don’t have many additives or preservatives. Mice are known to be scavengers and can digest any food that they find, but that doesn’t mean that they can consume foods without risking their health. Since you are taking care of a pet mouse, they will not be as robust as wild and city mice. Their stomachs will be more sensitive and will not be able to process additives and preservatives. Plus, pellets are the foundation of a mouse’s diet, so they will consume this food far more than fruits, vegetables, and other carbohydrates combined. They can also eat chocolate bits of egg and cook chicken if they need a protein boost. When you feed them fruit, only give them about a tablespoon and don’t feed them a serving more than twice in a week. Always keep their dish full of pellets in their cage so they can nibble on their food as they please.

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What lengthens a mouse’s life?

1. Exercise safely

Using their muscles and their energy throughout the day is important for mammals, including humans. Like mice, humans that do not move much throughout their lives can have their lifespan significantly shortened. One reason for this is because their cardiovascular system does not get enough exercise or stress, so it fails to become stronger. As our bodies become older, they become weak, and the cardiovascular system weakens as well. The same thing happens in mice. 

2. A healthy diet with a high variety of foods

Mice need to eat different types of food to be healthy. They should get a mixture of pellets, vegetables, fruits, and carbohydrates along with some seeds and nuts. You should never feed your mouse raw meat like raw beef and raw pork, and stay away from the citrus fruits, onions and garlic, and human junk food.


  • The typical lifespan for a mouse is about two years
  • Their lifespan depends on what type of species of mouse it is
  • Mice live half as long if they live outdoors compared to those who live indoors
  • Feeding your mouse a terrible diet will shorten its lifespan as well.
  • Nature is full of predators which also shorten their life spans as they’re eaten or attacked
  • Feeding a mouse cheese can cause intestinal distress and stomach pains