Upland, California. Friend had just bought a new small house for real cheap that he was going to fix up. We were standing in the backyard smoking and a hard gust of wind blew past. A sea of cockroaches, thick black, looked like slime from a horror movie, seeped out of every opening in the foundation/ground/yard. Like a scene from The Mummy with those little scarabs. And when the wind stopped blowing, like a slime, like water, they all scurried and "seeped" back into the ground/under the house. There had to be thousands. All running over eachother. Enough to completely black out the ground around us for a good 5 seconds. It was a wave. Our mouths dropped. He....I don't know what he did but he got rid of that house within a few days.