By Fred Bouchard Plague-ridden Saxony hired the legendary Pied Piper to toot rats out of Hamelin. Other age-old tactics—trapping, shooting, pan-banging—raise fresh collateral issues in densely populated areas, in addition to mess and noise. Chicago in recent years resorted to sniper stealth by siccing 1,000 neutered feral cats on its record rat population. Passive approaches to rat control yield slow results, as city-centric man confronts Rattus norvegicus, the world’s most populous and prolific urban mammal. Rat fertility is gaining ground as shorter, warmer winters encourage them to squeeze out an extra litter or three a year. Exterminators concur that the [READ MORE]