hampster care

Question
Hi,
 My name is Jen from PA.  I had got my daughter a hampster about 8 months ago.  About two weeks ago,  we decided to get her(our hampster) a friend.  We have an old 200 gallon fish tank that leaked water so we put our hampster in it.  We also have her old cage set up inside the tank.  We put the new male hampster in the cage and closed it, and let the old female hampster outside of the cage, so they can get use to each other through the bars of the cage.  Everytime we try to put them together, he goes towards her and she attacks him.  He seems like he is just trying to be friendly towards her,  but she just keeps attacking him.  How should I deal with this?  Is this attacking actually mating,  or is she really trying to hurt him?  Should I take him back to the pet store?  Please give me your feedback.
             Thank You,
                    Jennifer

Answer
The female probably feels threatened by him. A 200 gallon tank is to big for one hamster-- you could house a colony of hamsters in there! I would put a barrier in the middle until she gets used to him. Here is a usefull link about breeding hamsters:
http://www.ask-the-vet.com/breeding-hamsters-breed-hamsters.htm