Dwarf hamsters are gaining in popularity as pets and provide a smaller alternative to Syrian hamsters. Unlike Syrian and Chinese hamsters they can often be housed together in small same-sex groups of the same species if familiarised with each other while they are still young.
Although if you are planning to house two or more dwarf hamsters together then they will need to be roughly the same age and size, while they should also have been living as part of a group when bought.
Hamsters may squeal and chase each other at first as they establish a hierarchy, but this is normally just temporary and involves little physical conflict. If the fighting appears severe or lasts for more than a few days then they will need to be separated. Otherwise is it best not to intervene. Unfortunately, their smaller size, as well as their speed and agility, mean they are slightly harder to handle than Syrian hamsters and so less suitable for young children.