dwarf hamsters fighting

Question
hi, i have two dwarf hamsters that are brothers, and they are about four months old. I noticed that they got along very well . They would sleep together , cuddle together and all the cute litle things. But now, they fight all the time ! We actually have to get another cage just so they wont kill eachother!  The one hamsster seems like it owns the cage , it wont let the other one eat drink or sleep or exercise on the cage. What can be the problem ? Is that normal ?
Thanks very much!

Answer
Hi Alex

Unfortunately this is a very common with dwarf hamsters, especially Campbells.  When they are young they usually get on really well, but when they reach adulthood they can start fighting for no apparent reason as their personality changes.

The only real option is to split them into their own cages and once this has happened, you can never put them back together again otherwise the fighting will be very serious to the point of causing injuries.  Also, as you have found, one is bullying the other and if this is left to continue either one of them will be seriously injured (I have seen hamsters who have fought each other and some of the injuries are horrendous), or the one being bullied will die because they are so stressed, afraid to eat etc. I have found that once split into their own cages, the small one who is being bullied normally puts on weight and calms down a lot.

Once they have been separated the hamsters usually settle down pretty quickly and get on OK alone.  It is a nice idea that these little creatures are kept together but in reality this isn't always possible.  It will mean you having double the cleaning out tasks etc. but in the end it will be worth it.

Regards