Bed bugs are small, brownish, flattened insects that feed solely on the blood of animals. The common bed bug, Cimex lectularius, is the species most adapted to living with humans. It has done so since ancient times.
Adult bed bugs are about 1/4 inch long and reddish brown, with oval flattened bodies. The immature (nymphs) resemble the adults, but are smaller and somewhat lighter in color. Bed bugs do not fly, but can move quickly over floors, walls, ceilings and other surfaces. Female bed bugs lay their eggs in secluded areas, depositing up to five a day and 500 during a lifetime. The eggs are tiny, whitish and hard to see without magnification (individual eggs are about the size of a dust spec). When first laid, the eggs are sticky, causing them to adhere to surfaces. Newly hatched nymphs are no bigger than a pinhead. As they grow, they molt (shed their skin) five times before reaching maturity. A blood meal is needed between each successive molt. Under favorable conditions (70 - 90 degrees F), the bugs can complete development in as little as a month, producing three or more generations per year. Cool temperatures or limited access to a blood meal extends the development time. Bed bugs are very resilient. Nymphs can survive months without feeding and the adults for more than a year. Infestations therefore are unlikely to diminish by leaving premises unoccupied. Although they prefer feeding on humans, they will also bite other warm-blooded animals, including pets.
Bed bugs are typically active at nighttime, with a maximum attack period about an hour or two before sunrise, though given the chance, they may try to feed at other times throughout the day. Attracted by warmth and the presence of CO2, the bug penetrates the skin of its host with two hollow injector tubes. With one tube it injects its saliva, which contains anticoagulants and anesthetics, while the other tube withdraws the blood from its host. After a five minute blood meal, the bug returns to its hiding area. The bites are not usually felt until a few minutes or hours later. Although bed bugs can live for up to 20 months without a meal, they usually look for blood every five to ten days. They can be found on wooden slats, springs as well as the bed frame. They can also live in wallpaper crevices, electrical wall plates, light fixtures, wall hangings, cabinetry as well as carpet fibers and wooden floorboards. For their size, common household bed bugs are extremely fast.
Characteristically these areas are marked by dark spotting and staining, which is the dried excrement of the bugs. Also present will be eggs and eggshells, molted skin of maturing nymphs and the bugs themselves.
Another likely sign of bed bugs is rusty or reddish spots of blood on bed sheets or mattresses. Heavy infestations are sometimes accompanied by a "buggy" or sweetish odor, although such smells are not always apparent.
Bed bugs prefer to hide close to where they feed. However if necessary, they will crawl more than 100 feet to obtain a blood meal. Initial infestations tend to be around beds, but the bugs eventually may become scattered throughout a room, occupying any crevice or protected location. They also can spread to adjacent rooms or apartments.
Bites and Concerns Bed bugs usually bite people at night while they are sleeping. They feed by piercing the skin with an elongated break through which they withdraw blood. Engorgement takes about three to 10 minutes, yet the person seldom knows they are being bitten. Symptoms thereafter vary with the individual. Some people develop an itchy welt or localized swelling, while others have little or no reaction. Unlike fleabites that occur mainly around the ankles, bed bugs feed on any bare skin exposed while sleeping (face, neck, shoulder, arms, hands, etc.). The welts and itching are often attributed to other causes such as mosquitoes. For these reasons, infestations may go a long time unnoticed, and can become quite large before being detected.
Outbreaks can often be traced to international travel from countries where the bugs are common, such as Asia, Africa, Europe, the Caribbean,or Central/South America. This is a particular problem for hotels, motels and apartments, where turnover of occupants is constant. Bed bugs are small, escaping detection after crawling into suitcases, boxes and belongings. The eggs are almost impossible to see when laid on most surfaces. Purchase or rental of secondhand mattresses, box springs, and furniture is another way that the bugs are transported into non-infested dwellings
Once bed bugs are introduced, they often spread room to room throughout the building. Unlike cockroaches that feed on filth, the level of cleanliness has little to do with most bed bug infestations. Pristine homes, hotels and apartments have plenty of hiding places and an abundance of warm-blooded hosts.
Controlling infestations of bed bugs is challenging. They hide in many tiny places, so inspections and treatments must be thorough.