Introducing Dwarf roboroski PLEASE HELP!!

Question
I bought 2 dwarf robs from pets @ home last week and one died a few days later (of stress they told us) so we went back to get another for it but they said not to because they would probably fight. I got 3 more so now 3 are living together and 1 is on its own. they are all from the same litter and i want to introduce it so they can all live together. How do i do this?

Answer
Dear Jess,
thank you for your question.
Roborovski hamsters live as breeding pairs in the wild, in a huge territory and spending a lot of time apart. They also change partners when they don't get along any more. This is the reason why even breeding pairs often fight in captivity and pairs or groups of the same sex will fight in almost all cases. I don't recommend introducing the single hamster, it won't work and he won't be lonely by himself. Keep a close eye on the other three in case they start to fight, those fights can get serious very fast and may end with hurt or even dead hamsters.
I also recommend seeing a vet with the single hamsters. Hamsters don't just die from stress and it's important to make sure that it didn't have any disease that the surving hamster may have, too. www.rmca.org/Vets has a list of good rodent vets.
I hope I was of some help to you
Jennifer