I need help sexing my hamster!

[anushkals]

A friend of mine bought three dwarf hamsters from the pet shop in October. One of them started to hurt one of the other so she separated them and gave me two. The pet shop sexed them all as girls but as they are growing one of the two I have is getting a rather large bum, and I’m worrying they might be a boy. I attempted to sex them both myself but I’m a first time owner and can’t tell. They’re about four months old now.

[Jeir]

If you put the hamster in a clear glass and hold it on its side (obviously blocking the open end so the hammy doesn't jump out), you can lift it up so you can see your hamsters' undersides. A male would have an obvious rounded rump and two openings that are far apart, while a female would have a flatter rump, two openings that are very close together, and two lines of nipples on either side of the tummy. There are plenty of visual guides on the 'net to help with sexing if you need them.

[Engel]

Personally I would separate them regardless of gender just to be on the safe side and to avoid any fights in the future.

To be honest it's quite easy as the boys have huge testis. I hope this helps!!