NEW YORK—Bobby Corrigan, a world-renowned rat expert, grew up in Brooklyn reading mystery novels. He dreamed of being a detective, but instead used his sleuthing instincts and science credentials to become the Sherlock Holmes of rodent control.
One morning this spring, Corrigan, 73, stood in a small auditorium inside New York City’s health department. The room was church-like, with high ceilings, wood-panelled walls and frosted glass windows. Looming behind him, projected on a large screen above a wooden stage, was a whiskered rodent with a long naked tail.
