Infestations of bedbugs in Sweden have increased by more than 800 percent during the last five years, the Swedish pest control agency Anticimex said. Sven Jeppson of Anticimex told Sweden\'s The Local in an article published Tuesday that this year alone his agency was called out 2,951 times to deal with the bugs. In 2006, Jeppson said the agency dealt with only 317 cases of bedbugs. The small, parasitic insects resembling linseeds feed on blood, preferably from humans. Their bite can trigger allergic symptoms and may produce a skin rash. Jeppson attributed the increase in the number of bedbug cases to the fact that Swedes are traveling more and more tourists are visiting Sweden. To make matters worse, bedbugs are getting harder to kill. \"There seem to be more hardy strains around,\" Jeppson added. \"Many have grown resistant after having been exposed to a small amount of pesticide. Sometimes it is easy to get rid of them and sometimes it is nearly impossible.\"