those from petshop are usually not healthy at all.. i suggest u take a look at adoption thread http://forum.lowyat.net/topic/443156

which pet shop u buy them from?? maybe u can post some pic of them to let people here have a look at them @@ or bring them to vet for body check.. i bring mine to vet once in a while too, oni RM15/pig  cheap enough..

aww.. i saw their gp in pets fair last year in midvalley, terribly infected by mites, they put too many gp babies together in a small dirty cage    i got 1 of mine from there too last year, also infected by mites but my sister like her look too much so we bought her and send her to vet. now fully recover d 

hope urs isn't infected lor.. if they scratch too much then u should be careful d..

better let them get used to the environment 1st before playing with them @@ i think 1st page got the guide on how to take care of them..

Isn't hay is for GP to eat, not for bedding? Change the bedding for bedding materials.

Actually I noticed that my GP doesn't like the hays to be dirty by their pees & poos. They won't eat the dirty ones. Hehe. Sorry for unnoticed.

From my experience, if the GP avoid the pellet, maybe it doesn't like the pellet taste. However, if your other GP likes them, you just ignore the other one. Eventually, when it starts to get hungry, it will just eat the pellet. My GP used to be like that but eventually he just started eat the pellets anyway.

For the running, it's normal as energetic and normal happy GP likes to run around the cage cuz of curiosity, unless if spooked or scared of a person approaching or sudden moves.

For mites, just go to vet for check-ups. Maybe go to petstores and ask some tips. One more option that I read on an online pet blog says that to get a white piece of paper and put your guinea pig on it and wipe the paper all over him, if you see black specks/bug like thing you need to get him to vet.

mites are too small to be noticed by us.. but u can check their butt, forehead and ears, usually mites will feed on their ears and forehead, if u see closely sometimes u will notice some black or brown dots on their fur..

if really seriously infected, their fur will drop, leaving the infected area empty, then u should really go to vet immediately

using hay as bedding is common practice in those western country but seldom have ppl do it in msia i guess (our hay is not cheap  ) coz u have to change those hay everyday otherwise those dirty hay will carry some germs tat might make ur gp sick..