I just took out my ball python today for the first time in about a week and I notice today that when he breathes (not every time but a noticeable amount) he makes this wheezing/whistling sound. I did some reading and it sounds like it may be an URI. His humidity had been low for a while and so I just started spraying it to raise the humidity to around 60. Could this be a possible reason why he is wheezing? He is very active and seems perfectly normal other than making a whistling sound every now and again.

Any advice?