Russian dwarf hamsters fighting help

Question
I have 2 female russian dwarf hamsters who have lived quite happily in the same cage for the last 5 months but about 2 weeks ago they started to fight constantly and i've had to put them in seperate cages. Is there anyway to reintroduce them into the same cage as they dont seem happy now they are on ther own , one of them is a lot less active now and barely moves from its bed. As far as i can tell it isnt injured and when i put it in its ball it runs about as normal its just when i put it back in its cage. The one which is a lot less active is the one which was being bullyed by the other one, it also now also squeaks at me sometimes when i go to pick it up but it never did before. Please help I want them both to be happy again!

Answer
Hi Emily

this is a very difficult situation.  I'm honestly not sure if you will succeed. However, the only way I would try would be to put their cages side by side, then a couple of times a day for the next few days, swap them over so that they are in the other one's cage.  This way they'll smell the other one and get used to their scent.  When you've done this for a few days, assuming they are not going completely crazy when you mix them around, you could try reintroducing them - but in neutral territory.  If you have another cage/tank that you can borrow you could try this with new bedding - however, make sure you can get easy access to them if they start fighting so that you can separate them immediately.  Alternatively, thoroughly wash one of their cages and use this - in which case as their scent will still be in it even if you can't smell it, you need to mix some of their old bedding together.

If you manage to get them back in the same cage, keep a close watch on them for any signs of bullying/fighting - in which case you'll have to separate them again and accept that you're never going to be able to re-introduce them.  However, it is worth trying.
Regards