Like most animal species such as gerbils female puppies are very teretorial of their home and they want the males for themselves. I recommend next time you buy more than one pet that you get two males as they don't fight unless you train them to but that is illigal. Even when males are not around females are always fighting with eachother trying to be the dominant female.
Yes
yes they can because i have two females in the same cage
yup,
Unspayed females have shorter lifespans and tend to develop mammary cancer easier than a spayed female.
It depends on the female dog, not the gender of the puppy. Some old girls like all puppies, some do not. Introdue them slowly and see how it goes.
Well as you get older whether you a Male or a Female you just get them when you are mature and probably when the males hit puberty and the females get their period.
No
"Unnie" is written in Korean as "언니." It is a term used by females to refer to an older sister or a close older female friend. The pronunciation is similar to "un-nee."
That depends on your dog's temperment somewhat. The rule of thumb is to get the opposite. If the older dog is a male I would definitely get a female (make sure there is no accidental breeding though!). Two males are less likely to get along with each other. If the older dog is a female you may still want to get a female new dog, because females don't like to put up with young male dog antics. However, not all females get along with other females.
Assuming you mean Do nintendogs get older No they do not. Ever. They stay puppies FOREVER.
i dont have a girl so we dont have puppies we have a boy
well, sometimes.