My Rats Testicles

Question
Hi I recently got my new pet rat, about a week ago, and it seems that sometimes his testicles are bigger than others. They just seem to be getting larger to me, I don't know if this is just my imagination or if it is really occurring. I was just wondering if his balls will swell when he has to go to the bathroom or any other reason why this might happen, such as heat. Thank you so much for your time.

Answer
As long as they return to normal, this is pretty normal. Even a certain position can make them look bigger, swollen or even....um...lopsided.  ;)

Also, as long as they are not real angry red, blue or purple-ish in color and dont get super huge which may indicate a testicular abscess.