Hairless rat

Question
I just got my first pet rat.  She's a baby hairless rat.  She is covered in a grey fuzz but her hands, feet and belly are bald.  The fuzz is really thin, will it always be there or will she lose it?  I was wondering how long they live and if there are any special things, besides keeping her warm, that I should know about to better care for her.  I haven't gotten her a sister yet but I do have a female guinea pig that seems to think the rat is her baby. My guinea pig had a litter of babies before her mate was neutered and she was an excellent mother.  Is it safe for them to be together or should I keep them seperate?  For now they are seperate but they have playtime together and the mother guinea pig cleans and protects the baby rat.  The rat likes to snuggle under the piggy's belly.

Answer
Hi,
Some hairless rats have a little fuzz all of the time, some lose the fuzz. It depends on the breeding of the rat. as a cagemate except another rat. The rat will hurt and may even kill your guinea pig. Right now the rat is a baby. Rats sleep in the daytime, guinea pigs at night. They both eat different type of food and cage. They can't live together. Here is a website that has excellent rat care in general and hairless rat care.
http://www.rmca.org/Resources/rmcafaq.htm  
Ann