Roborovski worries

[Lula]

Well I've had my Robo's about 5 weeks now and I've just noticed today that one of the little darlings is a lot fatter than the other. I'm a bit concerned that either:
a) the fat one is not letting the thinner one eat well and instead is nicking all the nice food before Porridge.
b) that maybe my breeder got it wrong and the fat one is pregnant.

Is there a sure fire way to sex Robo's as there is with a Syrian? Any suggestions on what I should do?

[SnuggleHam]

There is a thread posted by babyboos on how to sex robos. http://www.hamstercentral.com/forum/viewtopic.php?t=824 If you cant hold them securely enough to get a look I recommend putting them in a clear container or glass jar to get a look at their underside. If you can determine that one is male and female that may answer the possibility of a pregnant hamster.

[babyboos]

they don't all grow the exact same size and can be quite different - some are fat and round and some are long and thin even from the same litter so don't panic too much until you check out their sex

i have three robs but all of them are different 1 is 1 1/2 inches a nother 1 is 2 in and diane is 3inches !