A solar-powered bug zapper works by harvesting the sun's energy during the day via solar panels built in on the top of the unit. These panels charge the bug zapper's rechargeable batteries, which typically work overnight after receiving eight to 12 hours of sun during the day. The bug zapper's UV batteries attract insects within up to half a mile, then kill them with an electrical charge of 300 volts.
Many flying insects are attracted to light, including UV light. At night when natural light sources are removed, they are drawn to the bug zapper and zapped by the light bulb's electrical charge. Bug zappers typically only attract flying insects.
Unfortunately, however, solar-powered bug zappers do not work well with biting insects such as mosquitoes, according to the University of Florida's Institute of Food and Agricultural Sciences. Mosquitoes and other insects that bite are actually more attracted to the smell of carbon dioxide than to light. When people and animals exhale carbon dioxide, the mosquitoes hone in on it with their ability to detect levels of 50 parts per million. Tests done at the University of Delaware showed that out of almost 14,000 insects killed with bug zappers, only 31 were biting insects. Many of the insects killed were those that are beneficial to the environment.