Damn tiny guinea pig penises!
We got a guinea pig last week from Mandi's Petsmart for free because it was born in the store. It appeared to be female, so I named it Gaz and all was good. She was skiddish as all hell, so we decided to get her a playmate today, as the guinea pigs were on sale. We found a nice calm one, put it in the cage with Gaz, and noticed something was wrong. Gaz started to vibrate with happiness and then tried to mount the new guinea pig. Turns out, Gaz is actually a boy and his bits were too small at the time to make an accurate call. His name is now Zim and he will be getting neutered in the near future so he can hump Lola all he wants and we won't have tons of little babies to worry about.