It’s easy to dismiss rats as just another cost of city living, but make no mistake: They’re shockingly destructive pests, teeming with harmful, disease-spreading bacteria and, according to one study, inflicting $19 billion worth of damage across the U.S. each year. Their relentless burrowing can erode a building’s foundation; their urine spoils tons of food each year; and their front teeth are like diamonds, strong enough to gnaw through wood, brick, and cement—not to mention live electrical wires, which can spark costly fires. [Full Article]