I accidentally disturbed a large gray nest that was in a small bush in my front yard. Before I knew it, these small black stinging insects (not sure if it was a type of wasp or hornet) started swarming me. I ran and luckily only got stung by one. I was just wondering if anyone knew what type of insects commonly build nests this low? I know I don't have a good description of them, but I'm just curious. They were small like the size of a fly, I didn't notice any colored stripes on it. The nest is fairly big and it is gray. It looks like it is made of mud. About 20 flew out, and I took off before getting a close look.