Yes. Especially if they'd never seen their own kind before.
Yes and fast
you shoudl not put a hamster and a guinea pig in the same cage no matter what.
No, not posible.
it shouldn't fight i know because i have guinea pigs and they don't have a real fight
Actually rabbits an guinea pigs are fine together. But maybe the female guinea pig is felling lonely being the only kind in the cage. Or maybe its because the rabbit just doesn't like the guinea pig. If it's possible you can try getting another female guinea pig or separating the the guinea pig and rabbits.
yes they will fight
Take a look at this link www.cavyspirit.com/sexing.htm
Thankfully, female guinea pig don't menstruate.
Well actually yes, they might fight. Males guinea pig's in general tend to fight with another therefor, it is a better idea to have two females or a male and a female together. But some males can get along, but usually males tend to fight.
it is not just the female guinea pig. all guinea pigs need exersise but never ever get a running wheel for the guinea pig their backs are so sensitive.
it is very uncommon that females fight, its mostly males that fight. if your female guinea pigs are fighting, separate them as they will fight until the other backes down or gets seriusly injerd. guinea pigs are herd animals which mean's they like the company. resons why your female guinea pigs might fight: 1) there finding the domanant female 2) the one female guinea pig is pregnent or has babys 3) one of the guinea pigs may be tretaning the other 4) one guinea pig may have never seen or met another guinea pig, so it could be scared 5) the guine pig is hurt and wants nothing to do with other guinea pigs 6) if the guinea pig is meen to you it is likely it wont like other guinea pigs 7)if the guinea pig is new and scared it may neglect or fight the other guinea pig 8) bad experiances with guinea pigs or animals 9) if there are already a pair of females and you put a third in, they may gang up on the other and seriusly hurt or kill it. hope i helped, thank you
it depends what type of guinea pig you have