Rats & Their Friends

My question is.......To save space in my already large growing petting zoo that i call my home......

Can My baby rat and my two baby guine piggies live in a double decker cage together as family????

I'm mostely concerned about health issues. They are still all babies and i'm just assuming they wont fight to terrably bad. All three are very freindly so far.

I have just recently purchased a rat as a pet. She is great!! Very very socialbal for how young she is, very playful, smart, and extemely cute. She is only i think a few months old, and i've been told she needs a friend. I would looooove to get another rat for her but i'm still unsure of the sex and i'm looking for a black or white&black rat which is hard to find around here. But i'm in no big rush, not to mention i'm all about adopting. She seems quite content with living on her own although.

Aaaaaaaanyway just this morning i get a call from my Animal Control friend and she just picked up Guine Pigs!!! And of course....."Jay you have to take one!!! They're all black and there's a runt who is just to cute" Well.....one turned into two little black baby female piggies. and like i said.....i need to make space for them. The rat is in a normal large rodent cage, but i have a double decker cage which i used for my chinchilla years ago. It's a Rodent Royal Retreat Play pen!! I'd assume all three could live in harmony.......Or can they???