how many hamsters in a cage?

Question
I was told by a friend that i can't keep my female and my male hamster together.They will kill each other. Is this true?

Answer
There are several reasons why not to keep both female and male hamsters together.  First reason is that they would breed and you would have baby hamsters up to your nostrils!  28 days is all it takes, plus when the female gives birth she will either fight with the male or mate again and have a second batch of babies when the first is ready to leave the nest.  Second is that hamsters have to be either very very young or be of the dwarf variety in order not to have too much fighting going on.  Dwarf hamsters are far more social than Syrian hamsters.    I personally do not recommend housing more than 1 hamster together because hamsters are naturally solitary animals.

Depending on whether or not one hamster is more territorial than another will determine if they would kill each other when housed together.  I also do not recommend housing both female and male together for obvious reasons (breeding out of control).