Absolutely!!! Guinea pigs love company.
HOWEVER they must both be the same sex because guinea pigs are too small to neuter and even if they don't get along the female will probably end up giving birth to a litter of at least 1-4 babies.
Double check the sex of the guinea pig you have and if you want another double check, if you're getting one from a pet store or a friend, it's sex.
Also two females usually get along better than two males, (not always the case). I would recommend you avoid two males and a female. They might fight.
I prefer already built cages over custom built ones as they tend to last longer. I got my guinea pig's cage here http://www.petproductsbyroyal.com/rabbit-guinea-pig/
This is not really a custom cage, but a cage with homemade penthouse on the top. http://www.guinea-pig-paradise.com/homemade-guinea-pig-cages.html
I try to clean my guinea pig's cage around once a week or when it looks dirty.
no
It means that the guinea pig wants to go back In its cage if not that then the guinea pig is cooled
You might see the guinea pig look around the cage and call for it. Whenever I take my guinea pigs apart the one that's still in the cage looks all around the cage and if he doesn't see the other guinea pig he starts squeaking.
No, paraketes need a bird cage not something made for a guinea pig. They have special needs for their cage so you need a bird cage.
not necessarily; if you leave one guinea pig in the cage with the sick guinea pig, the guinea pig that is not sick can get sick; you should separate them just to be safe but if the guinea pigs start to get lonely, put them back together
Yes because there is the after birth from the guinea pig
No its not, i guinea pigs cage is way bigger. & you should not have the same size of guinea pig cage as your hampster.
no
You may want to add extra bedding or a shelter for your guinea pig as they may just want to burrow. I got my last guinea pig cage here http://www.petproductsbyroyal.com/rabbit-guinea-pig/ and love it!