Is it normal for a chinnie to make a weird weezy/wheeky noise while he sleeps? I've heard Charley do this more often, and I'm not sure if its normal or if I should be worried. Suddenly I'll hear a noise that starts loud and slowly fades away...kind of like "WHEEE, WHeee, Wheee, whee", and when I got see him I notice he's in his resting/sleeping pose. Other than that he acts perfectly normal, should I worry?