Wierd things o. My hamster

Question
I have noticed wierd things on my hamsters bottom neir his tail. They are like two little ball-ish things really close to his tail. I have never seen them before and it looks kindof wierd. I have no idea wat it is. Are they like nipples or something? Oh ya, and they went away the next day, but then they came back, and now they're gone again? Wat do u think they were? Also, i'm not sure if my hamster is a boy or a girl?
    PS,    Thanks for answering :)

Answer
Hi Sam

By the sound of things your hamster is definitely a boy. I think you are describing his testicles. They can look very strange and appear lopsided, different sized etc and this is normal.  They are especially obvious at certain times - during the hot weather and when they have just woken up.  Hamsters can get testicular cancer but this isn't that common and there would be symptoms with this too, so I suspect there is nothing wrong as such.

I hope this helps you.

Regards
Sheila