Nobody knows how it happened: an indoor housecat who got lost on a family excursion managing, after two months and about 200 miles, to return to her hometown.Even scientists are baffled by how Holly, a 4-year-old tortoiseshell who in early November became separated from Jacob and Bonnie Richter at an R.V. rally in Daytona Beach, Fla., appeared on New Year’s Eve — staggering, weak and emaciated — in a backyard about a mile from the Richters’ house in West Palm Beach.“Are you sure it’s the same cat?” wondered John Bradshaw, director of the University of Bristol’s Anthrozoology Institute. In other...