are my hamsters fighting?

Question
i just recently received 3 hamsters as a gift. my first question is, how can you tell what kinda hamster it is? and how can u tell if it is male or female? i have a feeling mine are probably dwarves.  

next question, these 3 hamsters fight pretty frequently but i dont see any biting or much hurting.  just alot of bothering (ie. one will jump on the other one while it is eating or just pester it when it is sleeping).  they squeal alot but i wasnt too worried until i heard that dwarf hamsters are solitary animals.  is that true?

Answer
Dear Rebecca,
thank you for your question.
You need to seperate your hamsters as soon as possible. All hamsters are solitary and will fight. Even though the fights might not look serious, it is a lot of stress for the hamsters and the fights might get serious eventually and you might end up with hurt or dead hamsters - if not from the fighting, then from the resulting stress.
Dwarf hamsters can very well be housed in old tanks, you can get those cheap at garage sales or at pet shops (ask for damaged, no longer water-proof tanks). Each dwarf will need a cage or tank at least 2ft long, and 1ft high and wide with second storeys. If you use tanks, they have to be wider than high or at least as wide as high to ensure proper ventilation.  Use a mesh wire lid to cover the tank. The only problem is that you have to reach into tanks from above, which usually frightens small animals. I solved this problem by reaching into the tank at the far side of the hamster and letting him come to me.

Syrian hamsters are much bigger than all dwarfs, about 5 inches long. They come in all colours, but the original colour (very rare now) is golden with white belly. There are four kinds of dwarf hamsters that are more or less commonly kept. The Campbell's Dwarf, the Winter White Russian (or Dsungarian), the Roborovski and the Chinese Dwarf hamster. Campbells and Dsungarians look very much alike: grey with white belly and hairy feet, Roborovskis are tiny and sandcoloured and Chinese dwarfs look like mice, brown-grey with a long tail (at least for hamsters).
You will find pictures of all species and a lot of excellent hamster info on this page:
http://www.petwebsite.com/hamsters/about_hamsters.htm
The website has pictures of male and female hamsters and shows how to tell the difference, too (under "Breeding hamsters")

I hope I was of some help
Jennifer