Be prepared, I have a rescue so I have a lot of stories!
My Dad brought a guinea pig to me from a local animal shelter and has laid claim on him. His name is Marvin and in the morning they always get new piles of hay and fresh veggies, so he comes to the door and wheeks as soon as he sees you. If you open the door he'll stick his head out and take whatever you have in your hand away.
One pregnant one that we have, Tina, was housed with Bogo and they were always in the pigloo, were almost never seen out of it, and were both very skittish. Well, Bogo isn't her roommate anymore, Neg is. For some reason, Tina has changed completely. She is out all of the time, popcorns a bunch (which is funny to see with her belly ;D), and wheeks when she thinks you have something for her!
We once has two guinea pigs, Seno and Tiddles. Seno was about a year old and Tiddles was a couple of months old. Tiddles was the boss, no questions asked. One time Tiddles was chewing on some kale and Seno came over to get some. Tiddles took the kale, hit Seno with it, and then went in the pigloo with it and wouldn't let him in! Seno was like "alright, whatever." but it was hilarious to watch!
That's all!. We did have one guinea pig that used to throw food if he wanted attention though. OK, now I'm really done. ;D
Kimmie