Questions - rats

Question
I have a question about my rat, Phineas. She has been sounding congested. I can tell that it is coming from her nose. There is a little amount of poryphin around her eyes. Other than that, she seems to be completley fine. I haven't seen any changes in her diet; she is still eating and drinking, she is grooming herself, as well as my other rat, and she isn't sneezing or coughing. So I don't really think it's a respiratory infection/disease. Is it possible that she could be reacting due to the change in weather? Or I also thought that it could be food allergies--from a high-protein diet...Can food allergies go away on their own or is medication necessary?

I also wanted to ask...Is it possible for my two rats to be sisters even though one rat is albino and the other rat is a fancy rat?

And, my second rat, Ferb, tends to sleep on her back...? It is something she has always done. Is this weird?

I am so sorry for overwhelming you with questions!...lol. Thanks for your time! I look forward to hearing back from you!

Answer
First of all, sleeping on the back is fine, my one rat, Jackson, does it all the time, fat belly up!  It scares me sometimes seeing him like that but he loves to sleep that way. Its not super common, but they do it and its very cute when they do!!  He even sleeps on his side!

As for the congestion, she needs antibiotics. DOnt mess around with this or it can become chronic. Please see my website, sandyscrittercity.com and refer to the page on rat illnesses and focus on myco so you can better understand the importance of treating respiratory infections soon as they start.  You will need a very good vet though so let me know if you dont have one.

As for rats being related despite one has red eyes and white fur...yes, they can be.  I had a litter of rats, some had red eyes and white fur and the others were jet black with black eyes. I know they were related because I watched their mother give birth. She was a black and white dumbo. NONE of her babies had dumbo ears though.