In a study of the abundance “nuisance arthropods”—defined as any arthropods other than cockroaches or bed bugs—in homes, researchers at Rutgers University used sticky traps to sample arthropod abundance in over 1,500 apartments in New Jersey. Flies were the most abundant nuisance arthropod caught, and among flies, the most common (42 percent) were fungus gnats, such as these gnats in the genus Bradysia. (Photo by Whitney Cranshaw, Colorado State University, Bugwood.org)