guinea pigs sex

Question
hi, i got 2 female guinea pigs about 2 months ago but sadly one died. we have just introduced a new female friend but the older one is showing some strange signs which make me think maybe shes a male. She is doing a lot of loud purring kind of noises and aslo walking around swaying her hips in a slow kind of skulking way. I have also noticed her trying to mount lily whereas she never did that with daisy. What do you think

Answer
Hi Michelle

Well, first of all, we need to establish the sex of the two pigs for sure. Take a look at : http://www.diddly-di.fsnet.co.uk/Sexing-Guinea-Pig.htm

Also, if you gently press the pig's lower tummy, a little penis will pop out if male.

Having said all that, the behaviour is relatively normal even if both pigs are female. Basically, your older pig is telling lily that she is boss. The mounting is definately cause to check the sex though.

I hope that helps, but you know where to find me if you have any other queries.

Andy