New Mother guinea pig butting other female

Question
I recently bought a guinea pig at a pet store that was already pregnant and I did not know it until 10 days before she delivered.  My other guinea pig is younger and I bought her from a breeder.  The mother keeps butting and nipping at the other guinea pig and chasing it out of the igloo at night.  Is she just trying to protect the babies?  Hopefully she will no longer do this once the babies are adopted out.  

Answer
Hi Connie!

Mother guinea pigs are not usually terribly protective of their offspring.  I know that is against everything we are taught about animals, but that is why guinea pigs are born fully functional!  It's nature's way of protecting the young guinea pigs.  When you breed more than one sow at a time and the babies are born close together the sows don't even care which babies nurse off of which mom.  It makes guinea pigs wonderful adoptive mothers for orphaned guinea pig pups.

I think your older sow is just making sure the younger one knows who is boss.  As long as no one is actually getting hurt I would let them work it out themselves.  I think you should remove the igloo to encourage them to interact more.

One thing that is very important...  As soon as the babies are 4 weeks old remove the males!!!  Sooner if they start purring at the females.  Guinea pigs can get pregnant even before they turn 4 weeks old and the males can also breed back to their mother or the other sow you have them with.

Hope this helps!

Annie