brought in from other infested dwellings on a visiting person's clothing or luggage; Infested items (such as furniture especially beds or couches, clothing, or backpacks) brought into a home or business; Proximity of infested dwellings or items, if easy routes are available for travel, e.g. through ducts or false ceilings; Wild animals (such as bats or birds) that may also harbour bed bugs or related species such as the bat bug; People visiting an infested area (e.g. dwelling, means of transport, entertainment venue, or lodging) and carrying the bugs to another area on their clothing, luggage, or bodies. Bedbugs are increasingly found in air travel. Though bed bugs will opportunistically feed on pets, they do not live or travel on the skin of their hosts, and pets are not believed to be a factor in their spread. Diagnosis A definitive diagnosis of health effects due to bed bugs requires a search for and finding of the insect in the sleeping environment as symptoms are not sufficiently specific. It is difficult to distinguish bed bug bites from other arthropod bites and the linear pattern of bites (known colloquially as "breakfast, lunch and dinner" bites) is not specific for bed bugs. If the number in a house is large a pungent sweet odour may be described. There are specially trained dogs that can detect this smell. Detection Bed bugs can exist singly but tend to congregate once established. Although strictly parasitic, they spend only a tiny fraction of their lives physically attached to hosts. Once a bed bug finishes feeding, it follows a chemical trail to return to a nearby harborage, commonly in or near beds or couches, where they live in clusters of adults, juveniles, and eggs. These places may include luggage, vehicle interiors, furniture, bedside clutter—even inside electrical sockets or laptop computers. Bed bugs may also lodge near animals that have nested within a dwelling, such as bats, birds, or rodents. They are also capable of surviving on domestic cats and dogs, though humans are the preferred host of C. lectularius. Bed bugs can also be detected by their characteristic smell of rotting raspberries. Bed bug detection dogs are trained to pinpoint infestations, with a possible accuracy rate between 11% and 83%. Homemade detectors have been developed. Bedbug detectors, often referred to as "monitors", "traps" or "interceptors", use attractant based methods such as lactic acid or carbon dioxide (associated with