YES. It is normal, but it will continue until:
a) Baby is all grown up. (Not likely)
b) Baby is dead (sad, but true.)
The only thing to do is separate them.
when it is the pet of the month
No, it is not normal for a 10-month-old guinea pig to have only one big top tooth. Guinea pigs have four large incisor teeth, two on the top and two on the bottom. If one of the top incisors is missing, it could be a dental issue that needs to be addressed by a veterinarian specializing in exotic pets.
yes, you should bathe your guinea pig once a month.
Once A Month Is Normal ...
You should cut your guinea pigs nails once every month.
i recomend that you don't
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.
Once A Month...
yes
yes. I had a 2 year old guinea pig and a 6 month old and the were great together.
not often... only like one time every month because its expensive and i don't recommend you buying one from Petco i once bought a guinea pig from their and he died a week later and then i bought a hamster and he died within two months i do then again recommend you talking to a breeding and getting one through them or adopting one from a small pet animal shelter.
get a trainer or everytime it bites tell it off