Greenhead flies are a summertime nuisance in southern New Jersey, with July the very peak of fly season. In Holgate, on the southern tip of Long Beach Island, residents combat the irksome insects with ever more four-legged boxy structures that resemble grazing animals. According to the Holgate Taxpayers Association, the boxes, which lure and ensnare the pests on or near the marshland, are the most effective solution to the greenhead problem.

Rutgers University Department of Entomology concurs, noting online that after years of research directed toward control…