why does my ball python champ scratch his head all the time.I doubt that he has a repotory infection because hes not weezing or gaping or making any wierd noises.hes seeems fine other than the fact that hes scratching his head,hes eating and active at night.he usually does it when i spray the tank,he likes when i spray the tank because that is when he gets most active.can anybody help me in this.

Thanks,
Juan M