Now, hundreds of thousands of Norway rats, the kind that live in Chicago and don’t usually travel more than 150 feet from burrow to food source, suddenly are changing up their routines, boldly searching farther for food, including during the day — a shift for the normally nocturnal animals, said Robert Villamil, owner of Chicago-based Crow Pest Control Inc. Despite the explosion in rat boldness, the business has seen its commercial work slow with bars and restaurants closed or limited to takeout orders, as it’s been getting more business from residential customers.