Bed bugs are small, brownish, flattened insects that feed solely on the blood of animals. Although the common bed bug (Cimex lectularius) prefers feeding on humans, it will also bite other warm-blooded animals, including dogs, cats, birds and rodents. It has done so since ancient times; bed bugs are mentioned in medieval European texts and classical Greek writings back to the time of Aristotle.
Until fairly recently, most people (and even pest control professionals) had never seen a bed bug. Bed bug infestations actually used to be very common in the United States before World War II. But with improvements in hygiene, and especially the widespread use of DDT during the 1940s and ‘50s, the bed bugs all but vanished. The pests persisted, however, in some areas of the world including parts of Africa, Asia, and Eastern Europe. Over roughly the past decade, bed bugs have made a dramatic comeback in the U.S.― they’re appearing increasingly in homes, apartments, hotels, health care facilities, dormitories, shelters, schools and public transportation. Other places where bed bugs sometimes occur include movie theaters, laundries, rental furniture, and office buildings. Immigration and international travel have contributed to the resurgence of bed bugs in the U.S. Changes in modern pest control practice, less effective insecticides ― and a decrease in societal vigilance ― are other factors suspected for the recurrence.
Adult bed bugs are about 3/16” long and reddish-brown, with oval-shaped, flattened bodies. They are sometimes mistaken for ticks, cockroaches, carpet beetles or other household insects. The immature bed bugs (nymphs) resemble the adults, but are smaller and lighter in color. Bed bugs do not fly, and they don’t jump like fleas do ― but they can crawl rapidly over floors, walls, ceilings and other surfaces. Adult females lay their eggs in secluded places, depositing 1, 2 or more eggs per day, potentially hundreds during their lifetime. The eggs are tiny (about the size of a dust spec), whitish and hard to see without magnification, especially on light-colored surfaces. When first laid, the eggs are sticky, causing them to adhere to surfaces. At room temperatures, bed bug eggs hatch in about a week. Newly emerged nymphs are straw-colored and no bigger than a pinhead.
As bed bugs grow they molt, shedding their skin five times before reaching maturity. A blood meal is needed between each successive molt. Adult females also must feed in order to lay eggs. Under favorable conditions (70-80°F), the bugs can mature fully in as little as a month, producing multiple generations per year. Cooler temperatures or limited access to blood prolong the development time.
Bed bugs are very resilient. Nymphs and adults can persist months without feeding which is unusual for most insects. The ability to survive without a blood meal is longer at cooler temperatures ― potentially up to a year or longer at 55°F or less. In temperature-controlled buildings, a more typical duration is about 2 to 6 months. Consequently, it is usually impractical to leave buildings unoccupied in hopes of ‘starving out’ an infestation. When infested dwellings such as apartments are vacated, bed bugs often disperse to nearby units, or reduce their activity until the unit is reoccupied.
Bed bugs are active mainly at night. During the daytime, they prefer to hide close to where people sleep. Their flattened bodies enable them to fit into tiny crevices--especially those associated with mattresses, box springs, bed frames and headboards. Bed bugs do not have nests like ants or bees, but do tend to congregate in habitual hiding places. Characteristically, these areas are marked by dark spotting and staining, which is the dried excrement of the bugs. Also present will be hatched and un-hatched eggs, the tannish shed skins of maturing nymphs, and the bugs themselves. Another possible sign are rusty or reddish smears on bed sheets or mattresses from crushed engorged bed bugs. Although it’s often stated that bed bugs have a telltale “buggy” odor, the smell is seldom evident except in extreme infestations and should not be relied upon for detection.