Wow, I didn’t know this…http://www.control-mosquitoes.com/
They kill beneficial insects, attract mosquitoes but don’t kill them, help mosquitoes find standing water to lay their eggs, and spray insect fragments into the air. The Ultra Violet (UV) light from zappers attracts all night-flying insects. Each night zappers kill about 3,000 beneficial insects such as moths and butterflies, which pollinate flowers, but only a handful of mosquitoes. A Notre Dame University study in South Bend Indiana showed that people with a zapper in their backyard got bit 10% more than people without one because zappers attracted mosquitoes but did not kill them. UV light also helps mosquitoes find water where they lay their eggs. When UV light is reflected off the surface of water it is polarized. Like polarized sunglasses that reduce glare and help you see objects more clearly, the mosquitoes follow the polarized light to the water to lay their eggs. Because they attract large bugs, they are purposefully designed to explode them so they don’t accumulate and become a fire hazard. Exploding bug-fragments drift on the air. People and food nearby may be contaminated by insect-fragments from the zapper.