In 1996, University of Delaware researchers Timothy Frick and Douglas Tallamy published a study in the journal Entomological News. They had collected and identified the kills from six bug zappers at various sites throughout suburban Newark, Del., during the summer of 1994. Of the nearly 14,000 insects that were electrocuted and counted, only 31 (0.22 percent) were mosquitoes and biting gnats. The largest number (6,670, or 48 percent) were midges and harmless, aquatic insects from nearby bodies of water. The researchers claimed that killing this many harmless insects would disturb nearby ecosystems. According to Tallamy, most species of mosquitoes are not attracted to ultraviolet light, and certain species only bite during the day. Tallamy claims that bug zappers are worthless for reducing biting flies, exact a heavy toll on non-target insects and are counterproductive to consumers and the ecosystem.