oops there not both females

Question
I bought two female guinea pigs for my boys in June. A little over two months ago while holding one of them I realized one of them felt oddly fatter then the other and sure enough about 3 weeks ago she had babies.  One of the guinea pigs sold to us as female is actually a male.  Now I have two baby guinea pigs and more cages then I prefer.  My question is how old the babies need to be before they are given away.  Also can guinea pigs be spayed and nuetered.  My boys have become attached to their pets and I would hate to have to get rid of one but I don't have the space to keep them seperated.

Answer
Andrea -

This happens a lot with animals bought at pet stores.  The employees there are usually not properly trained in sexing "pocket pets" and will tell you the incorrect sex.  What I would do is start weaning (the males, especially) at around 2-3 weeks.  This is because male pups become sexually mature at around 3-4 weeks of age and you want to separate them from their mother before then to prevent inbreeding.  I would give them away at around 4-5 weeks.  Allow them at least a week of living on their own before you give them away.  

Here's one tip for you, though -- do not give them away unless you trust the new owners implicitly.  Sell them.  Often, snake owners will obtain baby guinea pigs to use as snake food, which is fine, as long as you don't mind explaining that to your children.  :)
Selling them at even a minor cost is a good way to prevent this from happening.

About neutering -- neutering the male is usually cheaper and easier than spaying the female, so that is what I would recommend.  Contact a good "pocket pet" vet and find out what their typical cost is.

Hope this is helpful.  If you have any more questions, please feel free to contact me.  Good luck!

Lorena