My male Rats are 6 months with no balls! Are they boys?

[Izzu.]

Male rat testicles are very prominent, even from a young age. When males are scared or uncertain, they can retract their testicles so that it actually looks like they don't have any. Although I have to say, considering how long you've had them for now, I would say that they've had enough time to 'show them off' - and Petco aren't exactly renowned for getting their sexes correct (from what I've heard).

Sexing a rat is very easy - particularly if you have both females and males to compare each other to. I had to sex my "oops" litter of mice (she was a rescue) for the first time last year, and even that was very easy to do - just on a much smaller scale! The first thing to note is that on females, the 'pee-hole' is CLOSER to the anus, whereas a males' penis is FURTHER apart from the anus. And obviously - they have balls! I've included a link in the sources below for you to reference to.

I would be aware though: rats can have up to 20 babies in a litter, and if the chances are that Elliot and Leo are in fact girls, you could end up with a heck of a lot of babies! If you really are uncertain of their genders, I recommend separating Bo from the other two - even if it is only temporarily - and seeking professional veterinary advice - although I'm sure you will be successful in sexing them yourself! It sounds like you have already determined their genders; if you can see nipples, then all signs are pointing to girls.

Considering the amount of time Bo has already been with the 'girls', the likelihood is that one - if not both - rats are pregnant. Even if you don't plan on keeping the babies, please ensure you have a large tank to house pregnant mummy in to have her babies (you will know if she is pregnant as she will begin to look much chubbier than usual and ROUNDER - almost as if she's swallowed a golf ball!). Remember that although you CAN house pregnant mothers together, it is not advisable due to fighting and 'tug-of-war' (I'm sure you can image). Also, if you cannot keep the potential babies yourself, I would recommend to begin immediately posting adverts and looking for people who will give some of the babies forever homes. Don't panic, though! Many people have "oops" litters. If you have Facebook, there are many rat lover groups online that will help you out with "oops" litters and advise you on how to proceed. It may not seem like much, but it feels so much better knowing that there are people supporting you!

In the future, just remember to never trust the pet store in terms of sexing. Always sex the rats yourself before bringing them home - just look for their testicles and you'll know it's a boy! If it doesn't have any and instead has nipples, it's a girl!

Good luck. If you need any more help then shoot a message my way. I own 9 rats of my own so I can tell you anything you need to know.