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Is It Normal for Hamsters To Bite Themselves?

(Last Updated On: July 15, 2022)

It’s always concerning when a hamster starts to bite itself. As this isn’t for dominance or defensive reasons, you may be puzzled by why your hamster has become self-destructive.

If your hamster is biting and scratching, it likely has an underlying health condition, such as an allergy, injury, mites, stress, or grooming difficulties.

If you don’t stop your hamster’s self-destructive behavior, its quality of life will be diminished and its longevity significantly reduced.

Is It Normal for Hamsters to Bite Themselves?

Under normal circumstances, hamsters don’t bite themselves or incessantly scratch their fur.

That said, hamsters are a cannibalistic animal species. The Journal of Comparative and Physiological Psychology found that up to 75% of mothers eat their pups within the first few weeks.

Male hamsters also cannibalize each other during territorial fights or when facing starvation.

So, for a species with a history of cannibalism, you may not be surprised if you find your pet hamster biting itself. However, incidents of hamsters biting parts of their body are rare.

Instead, a hamster with self-destructive tendencies is mostly influenced by external factors.

What Causes Hamsters To Bite Themselves?

Self-biting in hamsters usually results from health problems, physical injuries, or psychological issues. Here are the main reasons for this destructive behavior:

Fur Mites

If your hamster constantly bites and scratches, it’s most likely infested with fur mites. A hamster that’s infested with fur mites will exhibit some or all of the following symptoms:

  • Excessive scratching, leading to reddened skin
  • Loss of fur in the affected areas
  • Nervousness
  • Self-biting, particularly on the exposed, scaly skin
  • Difficulty walking

Additionally, a large infestation of hamster mites can affect the hamster’s behavior, potentially making it more active than usual.

To determine if your hamster has fur mites, closely examine the skin around its ears. Often, mites appear like tiny black dots on the fur. Further, the skin around the ears, nose, and feet will also appear reddish and inflamed.

Hamsters with fur mites will keep biting themselves, trying to get rid of the irritation caused by the mites. The scratching is usually an attempt to remove the mites causing the pain.

How to Get Rid of Fur Mites in Hamsters

A vet will perform tests to determine the following:

  • Type of mites
  • The extent of the infestation
  • Appropriate treatment

Usually, acaricides are the most effective way of treating mites in rodents and other animals. That said, mite treatment won’t be effective without sanitizing your hamster’s living space.

You can start by washing your hamster’s toys, accessories, food, and drinking bowls with soap and hot water. After that, spray the cage’s interior with an insecticide or acaricide solution.

Stress Levels

According to the National Center for Biotechnology Information, environmental changes can stress pet hamsters. At times, the stress can affect their behavior.

High stress in hamsters leads to destructive behaviors, such as cage rage and self-mutilation.

The former is where hamsters hit their heads against their cages in random moments of wild frenzies, while the latter is characterized by self-biting.

If your pet is stressed, it may seek relief and excitement in other ways, like biting off its fur or skin. The latter isn’t common and is mostly observed in hamsters with extreme levels of stress and depression.

hamster scratching and biting itself

Sources of Stress in Hamsters

To stop self-mutilation, you need to know what’s upsetting your hamster. The following are the main stressors to consider:


If you have multiple hamsters in one cage, the more introverted ones may be disoriented by the increased competition for food and lack of space, leading to depression.

The change in mental state may lead the hamsters to bite off their fur as a coping mechanism.

Social Defeat

Hamsters are usually loners, and they often get into territorial fights.

Unsurprisingly, the University of Tennessee found that hamsters that lose fights get so stressed that some go into complete social avoidance.

They occasionally lick the injuries they’ve sustained during fights, which may make you think they’re gnawing themselves when you see blood.

However, some defeated hamsters become suicidal from the stress and start to self-mutilate. Notably, this only affects male hamsters that live in groups.


Even though hamsters are mostly solitary creatures, extreme periods of loneliness can be mentally devastating. According to Neurobiological Stress, the key effects of social isolation include:

  • Reduced body weight
  • Increase in aggressive behavior
  • Changes in dopamine signaling in the brain

During these periods of isolation, hamsters may inadvertently bite off their fur for entertainment.

Stress Prevention Tips

Keeping your hamster happy reduces stress levels. To this end, here are ways to assist:


Despite being loners, hamsters also like affection and socialization with their owners.

So, play with your hamster at least every day. Ideally, you shouldn’t interfere with its space, but talk or sing to it whenever you can. If your hamster is the affectionate type, pet it as well.

Enrich the Cage

A boring environment is a common cause of stress, so make your hamster’s cage more interesting.

Apart from hideouts and running wheels, get toys and accessories like hamster hammocks, play tubes, chewing toys, and play bridges. These will keep the hamster entertained and let it exercise regularly.


Hamsters can develop allergies that make them feel itchy, extending to the point where they can’t stop scratching themselves. The most common allergy triggers include:

  • Harsh chemicals in cleaning solutions
  • Artificial coloring and sweeteners in foods
  • Fecal dust

Determining the type of allergen affecting your hamster involves trial and error. For example, you can try to reduce commercial meals for a few days and see if the scratching stops.

Existing Injuries

Hamsters can get into fights, climb on objects, and play with sharp items. All these activities can lead to injuries that may take time to heal.

It’s normal for hamsters to lick their wounds while their blood clots, sometimes throughout the healing period. It may seem like your hamster is biting itself when the wounds were caused by something else.

Small wounds heal by themselves once the blood clots, but a trip to the vet will be necessary for larger cuts. A lack of timely intervention can leave the hamster susceptible to bacterial infections.

Conduct body checks on your hamster, paying closer attention to the areas it is constantly biting or scratching. If you note any signs of cuts or blood, seek an appointment with the vet.


If you’re new to hamsters, you may be confused by their grooming habits. For instance, it may seem that your hamster is furiously scratching itself while, in reality, it’s grooming itself.

If you’re afraid your hamster is scratching itself too furiously, check the area for any scars. Most of the time, you’ll find that it was cleaning its fur.