one of my rats is sneezing very frequently about once evry 30 seconds, the other is fine. The one that keeps sneezing is a male dumbo about 7 weeks old. I dont think he has an RI because there is no discharge from his eyes or anywhere. I'm pretty sure it's something in his envionment. I keep them in my basement, which isny terribly dusty and isn't a storage basement. It is however fairly moist down there, and there is some mold on the walls. I have a feeling thet it could be their bedding though as when I take hime out of the cage the sneezing has decreased slighty, I use Great Choice brand aspen shavings. Anyone have any helpful advice?, Thanks!