female humping pregnant pig

Question
I have three guinea pigs: a mom and daughter, and another female. The mom has been dominant for months, but she is now prgnant and the other female (at least I think she is!) has been trying to hump the pregnant mom, who doesn't like it at all.

Is this normal? Can my "female" be a male (even though I see no evidence in her genitals)  Is it a problem for the prgnant sow?

Answer
Hi Monica

I would seriously question whether the humper is female or male. Take a look at the link below which shows you the difference between the boys and girls. Its not as obvious as you might think.

Andy

http://www.diddly-di.fsnet.co.uk/Sexing-Guinea-Pig.htm