It must be a normal part of our anatomy as I have this sensation as well of them going in and out of this hole from my windpipe to my food pipe, every day. I know EXACTLY what you are talking about as the same thing happens to me.
It is very unsettling.
Do you get "pieces" coming up in your throat as well? larvae?
I get the "burning" too, its just awful, mostly between the breastbone, sometimes radiating into my upper back.