The common bed bug is a small (5 mm long, 3 mm wide) oval, flattened insect that is brown colored, lacks functional wings and has a 3-segmented beak that tucks into a ventral groove under the head.

Bed bugs are nocturnal and feed only on blood – generally that of mammals and birds. Their growth and development is by gradual (incomplete) metamorphosis (egg---nymph---adult). They prefer to live in loose groups or clusters and these groups are usually found in cracks, crevices or other similar harborages. Although they are most active at night, bed bugs will also feed under low light conditions during the day. Bed bug bites are typically painless and usually are not detected while the bugs are actively feeding.

Bed bugs have an unusual mating behavior that is known as traumatic insemination. The male bug penetrates the females body with a modified copulatory organ called a paramere and injects sperm into her body cavity (hemocoel). The sperm migrates through the hemocoel to the female's primary reproductive tract. Females produce small (1 mm long) whitish eggs and cement them to harborage surfaces. A female can lay 1 to 5 eggs a day and more than 200 during her lifetime. There are 5 nymphal stages prior to the adult and at least one blood meal is required, per stage to successfully transition to the next stage. Under favorable conditions of environment and nutrition, bed bugs can live for more than 10 months. Both adults and nymphs can live for several months without feeding.