How Long Do Rats Live?

Being considered pests and pets at the same time, rats have nevertheless been a part of human lives for as long as we can remember. Despite being present all around the world, rats don’t have very long lifespans apart from a few exceptions. These small mammals can be terrific and entertaining pets – they rarely bite, are easy to keep, and are highly social and intelligent. However, life expectancy is something to be considered if you’re looking for a long-term companion.

If you’re looking to bring home a rat as a pet or are just curious about the rat lifecycle, we’ve got you covered! In this article, we’ll go over the average rat lifespan, lifecycle, and information about how to improve the quality of life for your pet rat.

Average Rat Lifespan And Lifecycle

Most rats (with the exception of a few species) usually have short lifespans. Domesticated pet rats normally only live 3-4 years – but the longest-living rat lived to be 7 years old in captivity! A captive rat’s life expectancy is much longer than their wild counterparts, who typically only live for 1-2 years. This is because rats in the wild are subject to predation, disease, lack of adequate food and water, and veterinary care – all resulting in a shortened life.

Rats have very high metabolisms and incredibly high heart rates (300-500 beats per minute!), which is part of why they have such short lifespans. Genetics also play a role in determining how long an animal lives. While rats have short lifespans compared to other domesticated mammals, some breeds may have even more disadvantages. For example, hairless rats typically have more health issues, resulting in a shorter life expectancy. 

Rats become sexually mature by the age of 40-75 days old. Males can be differentiated from females by the age of around 4 weeks. Females usually live longer and mature earlier than males. A female can have 6-13 babies in each litter, and newborns are born without senses or the ability to walk. They are completely reliant on their mothers for the first two weeks of their lives. Young rats wean off when they are 21 days old.

The Longest-Living Rat

Unlike most species of rat, there is one that lives an extraordinarily long life: the Naked mole rat. The naked mole rat is of great interest because it lives unusually long for a rodent of its size (up to 32 years) and holds the record for the longest-living rodent.

The reason for their longevity is debated but is thought to be related to their ability to substantially slow down their metabolism in response to adverse conditions, and so prevent aging-induced damage from oxidative stress. Owing to their extraordinary longevity, their genome was sequenced in 2011. Transcriptome sequencing revealed that genes related to mitochondria and oxidation-reduction are expressed more than they are in mice and other rats, which may contribute to their longevity.

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Upon comparison of the DNA repair transcriptomes of the liver of humans, naked mole rats, and mice, it was found that the longer-lived species (humans and mole rats) expressed DNA repair genes at a higher level than mice did. The findings suggested that DNA repair facilities increase longevity, and also were consistent with the DNA damage theory of aging. 

Why Do Some Rats Live Longer Than Others?

Genetics can play a significant role in the health conditions and lifespan of pet rats. However, most life-threatening health conditions in pet rats are secondary to poor husbandry. Husbandry is an all-encompassing term relating to the habitat, diet, and care of animals.

A proper diet for a pet rat is crucial. They should have good quality pellets and be offered some vegetables daily, in addition to fresh water. Small, occasional amounts of fruit or lean meat are also beneficial to a rat’s longevity. Your pet rat’s weight should also be monitored, so they don’t get obese as that can cause health complications as well.

Rat teeth are constantly growing throughout their lives and tooth overgrowth and misalignment are other common problems. They need to chew and gnaw throughout the day to make sure their teeth are worn down and not overgrown.

How To Improve A Pet Rat’s Lifespan?

Even though they have really short lifespans, there are still many things you can do to improve the quality of your pet rat’s life. Some of them include:

  • Keeping your rat’s teeth healthy – rats have teeth that grow continuously throughout their lives and need to be maintained, either through regular vet visits or through chews and treats. Giving your rat wooden blocks or other vet-approved items to chew on can ensure that they have healthy teeth.
  • Look out for signs of hair loss – one way to tell if a rat is getting old or ill is if it has started losing hair. Signs of balding or hair loss could be an indication of a deeper problem. Many infections can cause hair loss in rats, so any visible signs are significant enough to make an appointment with your vet.
  • Frequent (every 6-12 months) veterinary examinations – like all pets, rats need to have regular check-ups at the vet too. Regular examinations will help you catch problems early on and treat your rat accordingly. Your rat’s periodic bloodwork and fecal parasite testing are just as important and should be conducted on a regular basis.
  • Weigh your pet rat weekly to document any changes – being overweight or obese can cause health complications for a rat. Monitoring your pet’s weight can not only prevent obesity but help you identify any signs of illness or irregular weight changes. Weight loss is also the most common first sign of a sick pet rat.
  • Feeding only rat-specific pellets – talk to your veterinarian about how much and how often to feed. Follow a feeding schedule so as to not over or under-feed them.
  • Keeping your rat’s cage clean and free from waste odors – your rat could develop respiratory issues because of an unclean habitat or waste odors.
  • Getting your rat neutered before the age of 5 months – this reduces the risk of mammary cancer and is recommended by vets.
  • Make sure your rat does not have access to cords or tight spaces – domesticated rats have poor eyesight and can get stuck or seriously hurt.
  • Socializing with your rat – rats are very social animals and require mental stimulation. They should be let out of their cage for at least an hour a day and provided with toys.
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Diseases That Affect Rats

Some of the diseases that cause health complications for rats include: 

  • Heart disease is a leading cause of death for rats, and it often results from a genetic defect or condition that affects the heart muscle.
  • Cancer is also one of the many health complications that rats have to face; it can affect any body part. Options for the treatment of cancer in rats are available but they often prove to be unsuccessful – leading to early deaths of the affected.
  • Respiratory contaminations are the most well-known reason for death in youthful rats and can be brought about by different infections, parasites, or unclean environments. 


Rats are surprisingly social creatures, especially ones that have been raised as pets. You can train your rat to perform tricks and spend time with you. They have excellent memories and can learn to perform complex tasks. Domesticated rats enjoy the company of their human sidekicks and could be wonderful companions if trained well and handled with care.

In conclusion, rats definitely do not live for that long, but they live to the fullest and are extremely intelligent mammals. When provided a balanced diet, exercise, and adequate care and attention, domesticated rats could live up to 6 or 7 years. 

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Nadine Oraby

My name is Nadine; I am a passionate writer and a pet lover. People usually call me by the nickname “Joy” because they think that I am a positive and joyful person who is a child at heart. My love for animals triggered me to create this blog. Articles are written by vets, pet experts, and me. Thanks for visiting. Your friend, Nadine!

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