Know Your Bedfellows

Formal name: Cimex lectularius

Appearance: Flattened, oval, wingless and reddish-brown. (The insects grow darker after feeding.)

Size: Hatchlings are about the size of a poppy seed; adults reach about a fifth of an inch in length.

Feeding habits: These bloodsucking -- or hematophagous -- parasites typically feed every three to five days, injecting a little saliva as they do so and leaving small red bumps known as papules or wheals.

Peak activity: At night, usually between 3 and 4 a.m. Typically dormant during the day.

Effect: Bites tend to begin itching anywhere from minutes to hours later. Bedbugs aren't known to spread disease to their human hosts, though some people develop allergic reactions.

Hosts: Bedbugs will feed on any mammal, including dogs and cats. Migratory birds and bats have also been sources of infestation in the United States.

Life cycle: A female lays clumps of about five whitish, flask-shaped eggs a day. These hatch after about seven to 14 days into nymphs, which mature over several months, moving through five stages before molting and emerging adult.

Life span: Adults live for about a year. They can survive for several months at a stretch without feeding.

Favored hiding sites: Mattresses and box springs, as well as cracks and crevices in furniture and walls.

Climate: Bedbugs enjoy warm temperatures and are killed by exposure to extreme heat or cold.

Control: For a management plan, visit the Harvard School of Public Health Web site.

SOURCES: Mayo Clinic, Harvard University.