I've recently bought two russian dwarf hamsters from my local pet shop where the assistant said both were boys. We originally kept them in the same cage however one of them became increasingly dominant and they kept fighting to the point where one became injured.
After this we decided to separate them into different cages. However, one of the hamsters (the one who is usually very sweet natured and easy to hold) has become very private and refuses to let me hold him hissing everytime I try. Previously in his old cage with the other hamster he was so easy to hold.
Not only this but he has put on a lot of weight in the last few days and appears to be nesting.
Im wondering whether or not this hamster is in fact a girl and is pregnant.
Ive tried to tell the sex but its difficult.
Can anyone help me?