Do you have a pet mouse and thinking of getting a hamster or have a hamster and thinking of getting a pet mouse?  

Are you wondering if they would get along?  Yes, they can but there are some important things to consider first.  

Mice And Hamsters Characteristics

Yes, the two species do look similar but in character, they are relatively different.


  • They are more sociable but need to be in same-sex pairs, females if possible in a cage.
  • If mice are kept alone, they can become depressed so it is recommended that you have several mice in one large cage.


  • They prefer to be alone and kept in a solitary enclosure
  • They are territorial
  • When hamsters get into a fight, it is a fight to the death.
  • They like their own food and their own sleeping space
cute hamster

Mice And Hamsters Together — What to Consider

1. Do Not Put Adults Together

If you have adult hamsters and mice, it is advisable not to keep them together.  If you do, this can cause aggression between them.  In time, there will be competition between them.  Although this might surprise you, a hamster can be aggressive to other adults, especially the Syrian hamster. 

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Mice can become aggressive towards other adults too.  Eventually, competition for space and food will creep in, causing it to become a game of survival of the fittest.  Even if the mice mean no harm toward the hamsters, they will likely attack your mice.

2. Males Should Not be Kept Together

Males should never be kept together, no matter if they are male hamsters and mice or two male hamsters.  Mice males might get along well but you can still see some aggression between them.  Males can be territorial when it comes to where they live.

3. Consider Dwarf Hamsters

This is one of the friendliest hamsters’ species you will ever see.  They are not that big; compatible with mice in size.  This means that you can keep them together peaceful because one is not bigger than the other. 

Make sure that you are choosing the right type of dwarf hamsters.  You do not want to get a Syrian because they can be aggressive, even if they are a dwarf hamster.

grey mouse

4. Make Sure to Give Them Enough Room

Although they can co-exist, you have to make sure that they have enough space to live and operate normally.  This includes giving them space to ride their wheel, move around, and places to hide. 

You want to make sure that they get enough food or they could suffer because of the others getting aggressive and territorial.  This can cause a lot of stress so don’t keep their cages too close together.

5. Feed Them Enough

You need to make sure that you are feeding them frequently and enough.  You want to make sure that all of them get enough food but make sure that you do not overfeed them.  Observe them to make sure that all are getting enough to eat.

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Can Mice And Hamsters Breed?

The answer is simply no, not even a dwarf hamster and mice.  It might be interesting to see what their babies look like but though they look similar, they are two different species.  

Why They do Not Get Along?

The main reason that they do not get along and cannot be in the same cage is that hamsters are solitary animals and it would upset them to have mice sleeping where they do and eating what they eat.  The hamster would get upset thinking that one day they may not have enough food or place to sleep.

If you had two mice and one hamster, there is a chance that if aggression breaks out, the two mice would gang up on the hamster and possibly kill the hamster.  The hamster may kill the mouse if there is just one if they start to steal their food.

Can They be Kept in The Same Cage?

It is a bad idea to put them both in the same cage; it is a recipe for disaster.  If you have aggressive mice and hamsters, you may not be able to even keep them in the same room.  The smell and sight of each other could cause this aggressive behavior so you will have to put them in a different room.  They could even try to bite each other through the cages if they are close enough together. 

Size of Their Cages

  • Mice—for one mouse, the cage needs to be 10 x 12 inches and can work for three female mice to live together.  A male mouse needs slightly more room of their own but they can become territorial if they have too much space.
  • Hamster—they need a cage that is at least 12 inches high and 24 x 12 inches.  This is for just one solitary hamster. 
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  • Hamsters can become aggressive and kill the mice and mice can also kill the hamster.  It all depends on the injury that they have caused each other when they were aggressive to each other.
  • Mice can live in a hamster cage as long as they get enough food to eat and have the right conditions but it depends on how many animals are going to be in the cage.
  • Although they can live in separate cages, they really cannot cohabitate as mice are social animals and hamsters prefer to be alone.
  • The hamster can get stressed out because the mice are trying to invade their personal space.
  • If you want to have a hamster and mice, make sure that each one has its own cage.  If you leave them out to play together make sure that they do not fight and are getting along.
  • You should choose either mice or a hamster 
  • Both are omnivores, but hamsters like eat mostly vegetables and grains so if they are fed together with the same food, either the hamster or mice would not have their dietary needs met.
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Hi! I'm Anna and I´m a certified cynologist (KAU, ACW). Expert, blue cross volunteer, owner of Chinese crested kennel "Salvador Dali" and breedless friend called Fenya. "I can't imagine my life without dogs and I totally support the idea #AdoptDontShop".