Largely eradicated as pests in the United States in the early 1940s, bed bugs have been resurgent in the past decade to near epidemic proportions.
Reportedly, bed bugs have shown capable of infesting a variety of institutions and different types of businesses including nursing homes, furniture rental stores, hospitals, jails, homeless shelters, movie theaters, cruise ships, public housing, moving vehicles and public transportation, etc.
There are several ways in which dwellings can become infested with bed bugs. One common way is for them to be picked up while traveling or when staying at temporary lodging such as hotels, bed and breakfasts, or motels -- which are places that have been traditionally associated with an increased risk for housing bed bugs due to their higher rate of turnover and continual influx of temporary residents. Once acquired at such travel locations, the now hitchhiking bed bugs may then be transported and brought back to the homes of the guests in their luggage where a new infestation can then take place inside the home.
When bed bugs are brought into apartment building the problem becomes much worse. Within as little as a few weeks they can travel through the walls and spread throughout the complex resulting in a major infestation.
Adult bed bugs are reddish-brown, flattened, oval, and wingless. Bed bugs have microscopic hairs that give them a banded appearance. Adults grow to 4–5 mm in length and 1.5-3 mm wide. They do not move quickly enough to escape the notice of an observer. Newly hatched nymphs are translucent, lighter in color and become browner as they molt and reach maturity.
Parasitic in nature, bed bugs are bloodsucking insects that feed by hematophagy. They are normally active at night just before dawn, with a peak feeding period of about an hour before sunrise. Bed bugs may attempt to feed at other times if given the opportunity and have been observed feeding during all periods of the day.
They reach their host by walking, or sometimes climb the walls to the ceiling and drop down on feeling a heat wave. Bed bugs are attracted to their hosts by warmth and the presence of carbon dioxide. The bug pierces the skin of its host with two hollow feeding tubes. With one tube it injects its saliva, which contains anticoagulants and anesthetics, while with the other it withdraws the blood of its host. After feeding for about five minutes, the bug returns to its hiding place.
The bites cannot usually be felt until some minutes or hours later, as a dermatological reaction to the injected agents, and the first indication of a bite usually comes from the desire to scratch the bite site. Because of their natural aversion for sunlight, bed bugs come out at night.