STOPPED ZAPPING! I set it up and plugged it in and it zapped bugs like crazy. 30 minutes later I went back out to the yard and everything was suspiciously silent. The bulb was on...bright as when I first turned it on. Bugs were still buzzing all around it, but the zapping noise had completely stopped. Upon closer inspection, I saw insects crawling around the grid with impunity. I'll take a closer look in the daylight, but for now I'm very disappointed.