Habits

Overview – Habits – Concerns – Infestations – Control

Description and Habits

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. Bed bugs are mentioned in medieval European texts and in classical Greek writings back to the time of Aristotle. Other bed bug species prefer to feed on wild hosts, especially bats and birds.

Adult bed bug feeding on a human.

Adult bed bugs are about 3/16-inch long and reddish-brown, with oval, flattened bodies. They are sometimes mistaken for ticks or cockroaches. The immatures (nymphs) resemble the adults, but are smaller and lighter in color. Bed bugs do not fly, but can move rapidly over floors, walls, ceilings and other surfaces. Female bed bugs lay their eggs in secluded areas, depositing 1, 2 or more eggs per day and hundreds during a lifetime. The eggs are tiny, whitish, and hard to see on most surfaces without magnification (individual eggs are about the size of a dust speck). When first laid, the eggs are sticky, causing them to adhere to surfaces. Newly hatched nymphs are straw-colored and 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 (70-80°F), the bugs can complete development in as little as a month, producing three or more generations per year. Cooler temperatures or limited access to blood extends the development time. Bed bugs are 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 C. lectularius prefers feeding on humans, it will also bite other warm-blooded animals, including dogs, cats, birds and rodents.

Dark spots of bed bug excrement on a mattress.

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 eggs and eggshells, the brownish molted skins of maturing nymphs and the bugs themselves. Another telltale though less frequent sign is rusty or reddish blood smears on bed sheets or mattresses from crushing an engorged bed bug. Heavy infestations may have a “buggy” smell, but the odor is seldom apparent and should not be relied upon for detection.

Bed bugs prefer to hide close to where they feed. However, if necessary, they will crawl several feet to obtain a blood meal. Initial infestations tend to be around beds, but the bugs eventually may become scattered throughout the bedroom, occupying any crevice or protected location. They also may spread to adjacent rooms or apartments.