Just as students head back to college and families finish summer vacations comes the latest bad news from pest control companies: Bedbug infestations are getting worse and becoming more common in some places, including dorms, hotels, nursing homes, hospitals, office buildings, and schools and day-care centers. According to a survey released Wednesday by the National Pest Management Association and the University of Kentucky, pest control companies say there has been double-digit growth in infestations in the past year. About 54 percent of pest companies reported treating bedbugs in college dorms, compared with 35 percent in 2010; 80 percent reported treating...