Robert,
Just a thought regarding your experience. When I first started I had similar experiences and at times had tiny spots that felt like hot needles. Other times it felt as if a spider web was falling over my face. All somewhat disconcerting. Some of the hot, stinging spots were in my legs around the back of the knees. Since I am usually standing for about an hour I finally realized that the leg sensations were nerve endings. They have ceased at this time.
If you recall Master Lin's video he talks about the face mirroring all the parts of the body. In my case my "bug" sensation was mostly around my eyebrows, the side of the cheek and around the lower side of my nose. I got out my meridian chart and began to compare my "bug" spots with qi meridians. So far, in my case, every "bug" spot as well as the spider web feeling corresponded to a part of my body. Many of the sensations have almost totally ceased except for a couple of powerful burps while doing harmony of the universe. My personal conclusion was that these spots were merely areas of my body that were opening up and allowing more qi to circulate. As for the burps; I consider them to be old chi that wants to escape. Hope this helps. PS: Don't fear the bugs.
Don
