Recently, I noticed these tiny red flecks in my rex boy Geralt's fur. They aren't attached to the skin, and they're definitely not mites or fleas. My other rat doesn't have them. Any ideas? I can't really take a picture because the flecks are too small. I've been watching him for any changed behaviour but he seems fine, no problems at all. I was thinking it might just be dry skin or something associated to the fact that he is a rex, but I wanted to get a more professional opinion. Any idea what might cause this? Thanks!