My suggestion is to start head bobbing yourself. At that age, I do it to some of mine to humor myself. Just bob like 3-5 times every so often to gauge response. If they tilt their head just a little and give you the stink eye, then you are lucky. My own little superstition.
i tryed the bobbing thing and i got the stink eye.but not from the cham but from my wife that i did not no was behind me watching tell she asked .What are you doing ? i had no response . lol