I'm not sure what makes this brilliant invention work, BUT IT WORKS!
I've had trouble with summer flies (huge) and sewer "monkeys" (I call them that!) or drain flies or fruit flies - tried everything, drano, enzyme, vinegar, bleach, baking soda, hot water, boiling water - sprays, you name it - still have to find the source, but this fly "zapper" is getting it done! Bout to order another or 2 - little pricey, but if they work, it's worth it! So sick of flying bugs!!!!! Humidity and hot weather - bugs - ah well, such is life. Buy IT/THEM!
tried other "light" blue/ultraviolet and those didn't work, it's something to do with the fan, the bugs start sniffing around and it's like a quick sand, the get sucked right in - easy removal of "sticky" pad and replacement.