This is a bit off topic of clicking or popping sounds, but my adult male, Lars, sometimes grunts when im holding him. Not often, though. The noise comes from deep within him, and you can feel the grunts also with your hand near his lung area. Is this a behavioral issue, like he's just moody? Or should I be concerned? Again it only happens rarely, and I've only noticed it while holding him. Usually I can hear any noises he makes in his viv (the occassional sneeze [which is rare], rustling around in his substrate, etc), because its right next to my computer desk, and I never notice him doing this when hes alone in his tank. Anyone elses snakes do this?