HELP - Biting private areas

[elliesawers]

Hello, i am looking for some advice, i am a new owner to two female hamsters, every now and again when they're trying to get comfy they end up arguing and one starts squeaking, i have come to notice this only happens for a few seconds then they settle down. However i have noticed a few times now that one of them is nibbling the other one in its private area and that is sometimes what is making it squeak. What does this mean???!!

Also one of them is much thinner (not unhealthy but doesn't eat nearly as much) is this because we have changed their food from the pet store? they're still on muesli but from a different shop. or is one just a greedy pig? the fatter one isn't stealing all the food, they have plenty but the thinner one just isn't as interested.

[souffle]

I assume you have two dwarf hamsters ellie? This sounds like a case of bullying as the two mature. The small squables can quickly escalate to real fights and the target if often the genitals. More worrying is the fact that one seems small which indicates that one is dominating the food source and not allowing the smaller one to eat enough. This is as bad as physical bullying as the small one will be constantly stressed which is very unhealthy. Even with plenty food the little one is too stressed to eat it or process it correctly.
Personally I wold separate the two and keep them as singles. No play dates or anything as this will stress them. It may not be what you want but honestly they will be happier after about 10 days apart and will likely be more people friendly too.
If you choose to keep them together then you need to monitor them very closely for blood drawn.

[SimonandSyril]

This is most likely a territorial problem. If i was you I would play it safe and separate the girls