Hamster Behavioral Problems | Hamster Illnesses | Hamsters

Hamsters sometimes become aggressive, without any immediately obvious cause. However, there is nearly always a good reason for the behavior. It may simply be that the hamster has not been hand-tamed. This is a simple and important process. A new hamster will not have any familiarity with the human hand, and will act defensively – i.e. aggressively – as a result.

To find out how to tame your hamster, see the Holding a Hamster page of this guide.

Even if your hamster has been tamed, problem behaviors may still arise. These are triggered by illness or fear. Knowing a little hamster psychology will help you work out what the underlying issue us.

Hamsters may bite if they are stressed, afraid, or ill

Why Do Hamsters Bite?

If your hamster bites you when you hold it, there are several potential reasons:

Your hamster has not been tamed
If your hamster has only just been brought home, or has never been hand-tamed, it’s probably biting because it’s frightened of you. When you put your hand in the hamster cage, the animal will instinctively think the hand is a predator.

You are not holding your hamster properly
If you grab your hamster suddenly, it may bite out of fear. Move your hand towards your pet slowly, and then he won't be scared. Hamsters may also nibble you if you’re not holding them correctly. See the Holding a Hamster page for a guide to hand-taming.

You have woken your hamster too early
Hamsters are active in the late evening and at night, and will become disorientated and stressed if you wake them during the day. If they are confused and scared, they are likely to bite. Always play with your hamster during its natural waking hours in the evening, night or early morning.

Your hamster is mistaking you for food
Hamsters’ eyesight is very poor, and will usually nibble first and ask questions later! So, if you often stick food through the cage bars, and then do the same with your finger, the hamster will not immediately spot the difference.

Your hamster is unwell
Some medical conditions, such as mange or a wound, make a hamster very sensitive. Being handled will be painful for them in these circumstances. If your hamster suddenly objects to being handled, when formerly he was quite happy with it, it could be indicative of a health issue. Examine your hamster visually, or handle it wearing protective gloves if a visual check doesn’t reveal what the problem is.

Circling or 'Twirling'

A hamster that runs in circles continually is possibly be suffering an ear infection, or a brain injury. Take your pet to the vet for a diagnosis and treatment.

Fighting

If your hamsters fight, you’ll need to separate them, perhaps even permanently. If the fights are frequent, or if one aggressive hamster is preventing another from accessing food, you will have to intervene.

Syrian hamsters should never be kept in the same cage in the first place, after the age of six weeks when they mature. They are very territorial, and their fights can be fatal. Dwarf varieties sometimes turn on each other for no apparent reason, although it is often to do with not having enough space. If they fight, you will need a second cage in order to keep them apart.

Hamsters may fight, even species that can usually live together happily

Remove the hamster that is being aggressive and keep it in the separate enclosure for a few days. If the animals still fight when reunited, they will have to be permanently separated.

Sometimes hamster fighting is just an occasional bickering. If no blood is drawn, and if the flare-up appears to have died down, keep a close eye on your hamsters to make sure the fall-out is over. You can often stop these squabbles by having separate food bowls and water bottles for each hamster.

Severe scratching

The occasional 100-mile-an-hour back-leg scratching is normal. But if your hamster is continually scratching, even drawing blood in the process, he could have a health problem such as mites or mange. Give your pet a thorough health-check to try to determine the cause.

If you have started using a new type of bedding recently, this may possibly be the cause. Switch back to the old bedding for a while and see if the scratching persists. If the cause of the problem doesn’t become obvious, take your pet to the vet for a diagnosis.

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Comments

Heather, 11 November 2023

hi, i’m a new owner too hamsters. i’ve never owned one in my whole life, but i’ve always wanted one since i was little. I just got my first hamster back in january, and it’s the cutest little thing ever. she is a russian dwarf and her name is hamantha. (they couldn’t tell her gender, but it was very easy) when i got her, she was a little aggressive towards me. when id put my hand in her little box area she would often try to bite me. the lady had no problem with her at the pet store, so i didnt know what was wrong. i just thought she was territorial. fast forward too now, if i even try to put my hand in her area she immediately tries to bite me. i usually have too lure her into her little igloo then i kinda let her walk out onto my chest. she’s very nice when holding, and if you put her back she’s okay. i have another hamster, different breed but they aren’t in the same area. i’ve tried to let them meet but it didnt end well. but anyways, she’s really nice and doesn’t bite, like at all. she is a syrian and i heard they’re nicer then dwarfs. it took her a few months to warm up to me, but she still is not hand tamed. just like my other one. i believe they just have different personalities. they did come from two different animal stores, though. i’m just wondering why my dwarf bites me and will come up too my hand, but she doesn’t know to climb on. my syrian, just runs away from me. i feel bad for em bc ive dropped the dwarf a few times. she’s okay tho! any tips?

Bethany, 15 April 2021

I have just brought a Syrian hamster and I have never owned one before. I have not yet tamed her as she bites me whenever I try and I’m in the process of getting her a larger cage. Her current cage has a tunnel attached and she will sleep in there all day. The thing that concerns me is the fact that whenever she now goes into the tunnel, she will run back out as if running away from something. She also keeps scratching at herself. I think she may have mites but I cannot hold her to check myself. What should I do?

An Omleteer, 8 March 2021

Background: I’ve owned several hamsters over the years (mostly Syrians) so I’m educated on owning, caring and handling them. Current problem: We picked up a Robo ham 3.5 weeks ago and she has not warmed up to us at all. She is absolutely terrified of everyone. So much so that she gets around in her (large) tank UNDER her bedding like a mole. She will only pop her head out to get water and then she goes back into hiding and moving around in a sort of tunnel system she has created. If we ever walk over to her tank and she’s actually out, she will immediately run for cover like we are some sort of predator. We’ve never done anything to cause her so much anxiety. When we first put her in her tank, we gave her several days alone to adjust. I would have thought by now that she would be a little more relaxed around people but she’s still very frightened of everyone. I’m starting to think we got more of a pet to look at rather than handle or bond with. I feel bad for my daughter who picked out this hamster only to have it be nothing more than a goldfish to watch from a distance. Is there any hope for this hamster? I’ve read that putting them in the bath tub and sitting in there with them might help but I think that will only make her more scared.

Leanne, 29 May 2020

Hi, I have a golden Syrian hamster who has just turned 2 and a half years old, he's a lovley character and he's such a sweet animal very chilled, dosent mind being held never bites. All of a sudden as from yesterday he has become highly distressed and is scratching and running around the cage and chewing on bars ( never done this before). Iv checked his teeth they are a good size, his fur is in good condition with no bald patches, his eyes are bright and sparkly, checked him over for lumps couldn't find anything, eating and drinking fine urinating fine, his claws feel a little sharp, he's going bonkers in his cage, I don't understand we have no other pets, I would take him to a vet but covid 19 is making this difficult. I feel so sorry for him, I don't know how to help him.x

Leanne, 29 May 2020