Guineas make a grinding noise with their teeth

Question
Hi,

I am looking after my sister's three female guineas for a week and she told me some time ago - a few months or so - that one of them, Gwendaline, makes a grinding noise with her teeth, and I hadn't heard it until yesterday (10/07) and I was wondering what it means. She is the one who starts the odd fight - I'm assuming for dominance - and I wondered if this noise is her communicating that she's the leader? Is it anything to worry about at all?

Thanks :)

Answer
nah nothing to worry about, as along as she is not being too aggressive with the other pigs, the teeth grinding is a warning, i have a male that does it to me also so it is not just to other guinea pigs that they do it to. but yes usually the dominent or wanting to be dominent pig will make that noise, perfectly normal.