Location: Yorkshire, UK but my heart lies in Scotland!
Posts: 28,198
You should watch you hammies carefully poobearhamsy and check them frequently for bites and scabs. If the fighting becomes very intense with high pitched screaming and one losing weight and condition or if there is any blood drawn you need to separate them into individual cages and keep them apart from then on. It can happen very suddenly and they can hurt each other. In our experiance on the forum we have found that more often than not dwarf hamsters need separated due to fighting when they reach maturity.