russian dwarfs fighting

Question
my helper bought my kids 4 hamsters. we found one of the hamsters dead half eaten one morning, firstly we assumed it had been murdered by the others, then we remembered it had been chewing on a branch the kids brought home when it got lost in the house. we wondered if it could have died as a result of the eating the branch and the hamsters then eating it for recycling purposes.  as a result we got another to replace it and was careful to clean out cage and give them all a bath in powder before we put them to live together, although my son had introduced it briefly to the other hamsters in the old sawdust before i got home. now the big fat white one who was always a bit of a bully to the others has been attacking new one (white with greyish) along with the smallest brown one who runs the fastest who fights the new one a little too.  the third one is a nice friendly brown hamster who seems to be submissive to the other two when they get too close, and seems to get along with everyone.  do you think i could train them to live together at all or do you think i need to separate the two bully ones into separate cages of their own and ok to keep the other two together.  really hoped they could all live together nicely, but had to take out big fat white one after i saw he had chewed off the fur and made sore the new hamsters bottom, tail and nose.  felt so bad. some advice please would be greatly appreciated. the cage we have is 38 x 26 x 26 cm big, can't find many more bigger ones in petshop here in hong kong

Answer
Dear Stella,
thank you for your question.
If your hamsters as Syrian hamsters, then they need to be separated right away. They are absolutely solitary and will fight to the death. They only reason they haven't done so is the small cage and the fact that they are probably still fairly young.

Dwarf hamsters are more social, but living in a group of the same sex is not what their natural social live is supposed to be and it rarely works out. Introducing a new hamster into the group is pretty much impossible and a risk for all the hamsters. Since the group seems to be falling apart rapidly, I would recommend separating them all to make sure that they can't hurt each other anymore.

Syrian hamsters should each have a cage that's at least 100x50x50cm long, wide and high, for dwarf hamster the minimum is 80x50x50. It's difficult to find such cages almost anywhere, but hamsters really need that much space to run and dig like they need to. Fish tanks and rubbermaid containers (http://www.rubbermaid.com/Pages/Home.aspx) that are not higher than wide can be turned into good hamster homes, with a mesh wire lid to prevent the hamster from escaping. Ikea has storage containers that make good hamster homes as well, for example the Samla model.
Here are other homemade hamster homes:
http://www.tierische-eigenheime.de.tl/Gehege.htm
http://www.tierische-eigenheime.de.tl/*Schwedisch*.htm

I hope I was of some help to you
Jennifer