Hamster Life Cycle Guide

The life cycle of a hamster is not all that different from a human’s – they are born, they develop into adulthood, and they get old. What is unique about hamsters is the pace at which each developmental milestone is reached – hamsters mature rapidly and have a relatively short lifespan. It is important to understand the life cycle of a hamster if you have chosen to adopt one as a pet.

What is the hamster’s life cycle? Hamsters develop rapidly – they start out as tiny pups, reach adulthood in a mere four weeks, and are considered to be “senior citizens” in as little as 12 months. The lifespan of a pet hamster will vary by species, but on average is only 18-36 months.

A hamster’s short life is remarkable in both growth rate and reproduction. Read on for a complete guide on the life cycle of a hamster.

Hamster Life Cycle By Species

The hamster’s lifespan is what sets the pace for its unique life cycle. Lifespan will vary among the five hamster species – the Winter White, the Campbell’s dwarf, the Roborovski, the Chinese Hamster, and the Syrian. 

The Chinese Hamster, the Winter White, and the Campbell’s dwarf all tie for first place in shortest lifespan – living an average of only 16-24 months. The Syrian lives slightly longer, at an average of 2-3 years, and the Roborovski (Robo) typically lives the longest, at an average of 2-3.5 years of age.

It should be noted that these averages are for hamsters kept in ideal conditions in captivity – wild hamsters live significantly shorter lives, as they are often cut short by predation or harsh living conditions.

Hamster Life Cycle: Birth & Pup Milestones

As mammals, hamsters are birthed, nursed, and cared for by their mothers until they can live independently.

Baby hamsters are called “pups” and are born into a uniquely vulnerable state – they are hairless, blind, and deaf upon birth. They are also incredibly small – pups can weigh as little as a metal paperclip when born.

Baby hamsters are considered pups until they reach approximately four weeks of age, at which point they are adults and able to live independently. Hamsters are solitary animals, and once they are ready to leave the nest, they will live alone going forward, only coming together to mate.

During their four weeks as pups, they will reach several developmental milestones giving them the senses and protection needed to survive on their own.

• Day 5 of a hamster’s life: Approximately five days after a pup is born, he will begin to grow fur. This fur will allow him to control his body temperature and will provide protection from the elements. At this point, a pup will begin looking like a small hamster. 
• Day 10-14 of a hamster’s life: Between 10 and 14 days of life, a hamster pup will begin moving around and exploring her surroundings. Up until this point, she will have stayed in the nest with little mobility, relying completely on her mother for nourishment and her siblings for warmth.
• Day 14-17 of a hamster’s life: Between days 14 and 17, a hamster pup’s eye will begin to open. Hamsters have pretty poor eyesight in general, but the benefits that their eyes provide them will allow them to watch for predators and other potential threats. 
• Day 17-18 of a hamster’s life: At around 17-18 days of life, a hamster’s ears will open. Hamsters have an excellent sense of hearing, and they will use this to protect themselves when foraging in the wild. 
• Day 28 of a hamster’s life: At this point, a hamster is no longer considered a pup – he will be fully developed and ready to embark on his own solitary adventure. 

Hamster Life Cycle: Adulthood

Four weeks is remarkably young to be considered an adult, but such is the life of a hamster. In adulthood, a hamster will leave his family and will build his own burrow.

A hamster burrow is a series of underground tunnels that have multiple different chambers used for sleeping, food storage, and birthing (for females).

Hamsters are nocturnal animals and will spend their days in their burrows, only coming above ground when the sun sets to forage for food. Another important aspect of adulthood is reproduction.

Hamster Reproduction

The age of sexual maturity for hamsters can vary between species and even between individuals, but it is important to understand that a hamster can reach sexual maturity as young as 4-6 weeks of age.

Syrian hamsters tend to reach sexual maturity slightly earlier than the dwarf varieties, on average. Not only are hamsters fertile from an incredibly young age, but they reproduce at an astounding pace as well, for a few different reasons:

• Estrus cycle: Female hamsters go into heat every four days. This means that if a hamster does not become pregnant during her heat, she has a chance of becoming pregnant a mere four days later.
• Gestation: The gestation period of a hamster lasts for only 16-22 days, depending on the species. This means that once pregnant, a hamster will give birth in as little as 2-3 weeks’ time.
• Return to fertility: Once a hamster gives birth to a litter, she can return to fertility in as little as 24 hours.
• Fertile age: We have already determined that female hamsters can reach sexual maturity as early as four weeks of age. While this is an especially young age when compared to other mammals, it is also important to understand that female hamsters can remain fertile well into their senior months. The average hamster will be able to continue to reproduce until approximately 15 months of age (male hamsters will remain fertile until the end of their lives). 

A hamster’s reproductive period takes up almost its entire life – with females being able to reproduce from 4-6 weeks until 15 months of age and males being able to reproduce all of their adult lives.

This is a significant part of the hamster’s life cycle and one that should be taken into consideration, particularly if one keeps both male and female hamsters.

Hamster Life Cycle: Senior Pets

The point at which a hamster is considered a senior will depend on the average lifespan of its species. A Chinese, Campbell’s dwarf, or Winter White hamster will be entering her “golden months” at a relatively young age – being considered elderly at around 12 months of age.

A Syrian hamster will be considered a senior pet at around 18 months of age, and a Robo hamster should be considered elderly by two years. 

If you acquired your hamster from a pet store or an animal shelter, you may not know your pet’s exact age. If you are wondering at what point your hamster is nearing the end of his life, there are a few signs you can watch out for:

• Decreased activity level: As is the case with most mammals, a hamster may begin to slow down as he gets older. If you have had your hamster for more than a year and you’ve noticed he is not running on his wheel as much, spends more time on one level of his enclosure, or is unusually content to sit in your lap when being handled, these may be signs that he is beginning to slow down. This is a normal process of aging and should be respected.

• Decreased appetite: As a hamster slows down, he will not need as much energy from food sources. You may find him eating less and becoming less interested in treats he normally loved. His sense of smell may also begin to diminish, which will affect his foraging abilities.
• Increased sleep: In addition to a reduced level of activity and appetite, your hamster may sleep more often as he approaches old age. A hamster’s body will become tired more easily and more quickly as he ages, and it is normal for an elderly hamster to spend more time sleeping than he used to.

Of course, all of these symptoms can also be indications of an illness. If your hamster is relatively young and is showing a sudden decrease in activity level or appetite, you may want to consult your veterinarian.

On the other hand, just because your aging hamster is not showing any of these signs does not mean that he is not feeling the effects of his age. Your hamster may be running on his wheel and begging for treats right up until his last breath. 

Watching The Complete Life Cycle Of Your Hamster

While no one wants to think about the day that their pet may pass away, one of the unique qualities of owning a hamster is the ability to observe the complete life cycle in a relatively short period of time.

You can watch your hamster go from birth to adult to old age in as little as 18-24 months. While there is sadness in this thought, there is also a great privilege in being able to watch the circle of life to completion. Especially if that life was spent being cherished and loved by you.

You can learn more about caring for hamsters in my articles here.