A crackling flame lit up Harvey's chortling face from ear to beer. "Woooo, Vern, did you see that one?" he called to his buddy sucking down another Bud Light. "Man, looked just like a dang grease fire. Think we just fried a bat!"

Scenes like this play out in backyards across America every summer, as manly men filled with testosterone and fueled by alcohol prosecute civilization's eternal war against annoying insects. Their weapon of choice -- a bug zapper that combines the eery glow of a black light with an electrified metal grid to produce the snap! crackle! pop! of electrocuted insects that makes every minute sitting out in the black of night more exciting than a meteor shower.

"Zzzzzzzzzzzt!" snaps the bug zapper.

"Dang!" exclaims Harvey, taking another swig. "That beetle was bigger than a VW!"

Do Bug Zappers Actually Work? That depends on what you're counting on them to do. If you get a kick from igniting hundreds of moths, beetles, and other insects attracted to lights at night, yeah, they work. But they don't fry flies. More importantly, they don't attract the one insect that the vast majority of electric bug zappers are sold to attract -- the mosquito.

How come? Well, mosquitoes don't find people by sight. If they could, how could they locate you to bite at night? And lights don't attract them. Ever seen mosquitoes buzzing around a street light? No, they find you by smell. Humans emit a host of chemical molecules that mosquitoes hone in on and trace back to you. The most powerful of these is the carbon dioxide that you blow out into the yard every time you exhale. This is why dead people never complain about mosquito bites. Mosquitoes can't find them.

Admitting this fact, some bug zappers combine the black light and electrified grid with a chemical attractant, such as octenol. Unfortunately, octenol is much less effective than plain, old CO2.

So if a bug zapper doesn't kill biting insects like mosquitoes and flies, does it provide anything more than entertainment for rednecks as it immolates yet another moth? Nope. In fact, it does more harm than good by indiscriminately killing all winged insects that touch it. Many of these are beneficial insects that feed on or parasitize harmful ones. Others are important plant pollinators, while others end up as dinner for wildlife.

So if the evening's a little slow, nothing's on cable, and you and Vern just need an excuse to crack open a cold one, by all means, turn on that bug zapper. But you'd better not expose any bare skin come morning. Because Aedes mosquitoes -- the ones the transmit dengue fever, West Nile virus, eastern equine encephalitis, and Zika virus -- are most active during the day.