I bet most people with inquisitive minds take the time now and then to observe natural phenomina around them. Here's one such observation I've made over and over. Small insects the size of large gnats frequently swarm in my yard in summer. They come together in groups and in certain spots. The odd thing is that these spots can remain stationary for weeks. The regions where they swarm appear to be in the shape of a cylinder standing on one end, about a foot wide and extending as high as 6 or 7 feet. It's so obvious cause when a breeze blows the bugs off the spot, their swarming behavior ceases. Then they gradually find their way back to the spot. I've even noticed that a single bug flies normally until it enters one of the zones, then it's flight changes to small tight circles. These zones migrate around sometimes. I cannot detect any difference between the zones and any other spot. Are the bugs reacting to some field phenomenon? Any ideas?