One is always picking on the other

Question
We have 2 male hamsters in 1 cage. The one constantly picks on the other, meaning, doesnt let the other sleep, eat, use the wheel or roam around. When this happens, they make a screeching noise at each other and many times the one gets really mad and they end up in a physical battle. Why is this and what should i do?

Answer
This is because syrian hamsters (boy or girl, it doesn't matter) will fight as they age and should NEVER be kept together. You are lucky the territorial battles haven't left one dead. Get another cage for one of they boys and please separate them before the fighting escalates.