How Long Do Rats Live?

by Marissa Prizio

How Long Do Rats Live Image

Not all creatures age the same way, and this fact of life becomes drastically apparent when we welcome pet rats into our lives. These curious and cuddly rodents can make great companions, but it is important to understand how long their companionship normally lasts when you intend to keep rats as pets. Wondering “How long do rats live?” can help you decide if they are the best pet for your lifestyle and encourage proper care.

Just like dogs and cats, pet rats are dependent on their owners to make decisions for them. Many of these decisions can have a direct impact on their lifespan, so knowing life expectancy and striving to meet or surpass it is a great goal that drives the overall quality of care.

How Long Do Rats Live In The Wild?

 Rats are smart and nimble, but they are also small and plentiful. Wild rats in natural environments often find themselves towards the bottom of the food chain, which means the life of a wild rat is less likely to be as long as their domesticated relatives.

The same is true for wild rats that find themselves in less natural areas, like cities. Fewer wild predators and more food sources may sound like a recipe for success, but that isn’t always the case for a wild rat. Rats in these areas are able to find foods that are not naturally compatible with their physiology and humans often seek to eliminate rats from these areas. Both of these scenarios can result in poisoning.

Domesticated rats and wild rats may have the same genetic potential for survival, yet they have vastly different life expectancies most of the time. It all comes down to their care.

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How Long Do Rats Live In Captivity?

 On average, a pet rat has the capacity to live to be 2 years to 3 years old. This average life span is highly dependent on how well the rat is cared for and the medical decisions made by their owners. This life expectancy can drastically decrease if a pet rat’s needs are not appropriately met or they escape their home.

2 years to 3 years old may seem like a rather short life, but this is the average lifespan for many small rodents that are kept as pets. Also, most rat owners know that a short life doesn’t make for an unsuitable companion. As long as you are aware of how long your rat may live and are prepared to care for them throughout the course of that time, then their companionship can be just as fulfilling as any other pet.

The Life Stages Of An Average Rat

Rat years and human years are vastly different, and research has shown that rats age faster during some stages of their life. This means the ratio of rat years to human years is dependent on your rat’s life stage. Let’s break down the life stages of a rat so you are better prepared to make the most of your time together.

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Infancy & Baby

This is the earliest stage of life during which rats are maturing the most rapidly. This life stage generally lasts about six weeks and contains life events like weaning which happens around three weeks of age for young rats. During this phase, one year in a rat’s life consists of 42.4 days when compared to a human’s lifespan. 

Sexual Maturity & Adulthood

 Young rats become sexually mature around six weeks, but this is only a physical form of maturity and the exact age varies depending on the individual. This form of maturity is more closely associated with adolescence and gradually develops into adulthood. You can see this shift in displays of increased social behaviors and risk-taking. These behaviors can last into adulthood and during this phase of early adulthood 10.5 days is equal to one year of their life.

Once rats are socially and sexually mature they can be considered adults. At this phase in their life, the ratio of rat years to human years may decrease, but it is dependent on internal and external factors. Rats can experience early aging, much like humans can, if not properly cared for or predisposed to genetic conditions.

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Old Age

Between 15 to 20 months, rats experience biological changes that relate to changes noted in humans who are considered to be in old age. After these hormonal changes are complete it has been found that female rats only live around another 485 days on average. When compared to humans, this makes a rat-year in the tail end of a rat's life equivalent to 17.1 days.

What Factors Can Impact A Rat’s Lifespan?

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The life expectancy of a rat is influenced by a variety of internal and external factors. Genetic factors can be impactful, but since many pet rats belong to the species Rattus norvegicus, most genetic factors are widely shared. Pet store feeder rats and designer rats definitely have their differences, but a genetic predisposition to health issues can be difficult to determine without the genetic history of a rat regardless of their origins. and while we may not always be able to influence the internal factors, we can control many external factors. 

Diet, exercise, housing, supervision, a cage mate, and medical care are major points of external impact. When these aspects of care are properly provided they can increase a rat’s life expectancy, and when they are neglected the opposite is true. Extra steps, like spaying or neutering, can also be taken to prevent risks like pregnancy or cancer in certain reproductive organs. The quality of your rat’s start in life is also important, so beware of careless pet stores when you are looking for a new rat. 

Making The Most Of Your Pet Rat's Lifespan?

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All of this information on aging can be intimidating, but it provides valuable insight into keeping rats. The time you have together is short, but it can also be full of affection and memories. Pet rats may only be around for a fraction of our lives, but we care for them their whole lives. With a sound understanding of proper rat care and veterinary guidance, you can make the most of your pet rat’s life span.


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Author: Marissa Prizio
Marissa is a graduate of the University of New Hampshire with a degree in Bio Medical Pre-Veterinary Medicine. During her education, she enjoyed classes that ranged from scientific research to storytelling. Now, she blend those skills with her work experience in animal care to create written educational content for pet owners.

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