Normal?

While I was holding Zeus tonight, I noticed a small popping sound from him everytime he would breath out. It kind of sounded like a bubble popping. I looked at his nostrils and didn't see any kind of fluid or anything coming out of his nose. If y'all can give me some information on what might be causing this I would be greatly appreciated.

Sounds like he either has some stuck shed in a nostril, or the beginnings of a respiratory infection. I would bump the heat up a few degrees for a week, and see if that clears it up.