Ha HA! I totally did this. I was walking my dog on irving when the mailman, this old chinese guy, walked past. Just as he was a few steps behind me I mad this weird skwaking bird noise. Like, Kawwak! And he turned around and I turned aroud to, as if I was just as startled. There were these bushes around so maybe he though it came from there, although my dog knew it was me and barked, but she didn't give it away.